Falling hearts animation for browsers

Recently I have downloaded falling hearts animation from this . I have pasted the code below too. It simply displays a heart in my page.and falling hearts animation is not working.I am not able to identify the problem. will anyone tell me what changes I have to made in order to get the hearts falling animation.or is there any other code for the animation?

// **** Changed to Hearts from Snow ****

// Set the number of snowflakes (more than 30 - 40 not recommended)
var snowmax=12;

// Set the colors for the snow. Add as many colors as you like
var snowcolor=new Array("#aaaacc","#ddddFF","#ccccDD","#ffffff","#ffc0cb");

// Set the fonts, that create the snowflakes. Add as many fonts as you like
var snowtype=new Array("Arial Black","Arial Narrow","Times","Comic Sans MS");

// **** CHANGE YOUR IMAGE HERE ****

// Set the letter that creates your snowflake (recommended: * )
var snowletter="<img src=images/heart.gif>";

// Set the speed of sinking (recommended values range from 0.3 to 2)
var sinkspeed=0.6;

// Set the maximal-size of your snowflaxes
var snowmaxsize=40;

// Set the minimal-size of your snowflaxes
var snowminsize=20;

// Set the snowing-zone
// Set 1 for all-over-snowing, set 2 for left-side-snowing
// Set 3 for center-snowing, set 4 for right-side-snowing
var snowingzone=1;

///////////////////////////////////////////////////////////////////////////
// CONFIGURATION ENDS HERE
///////////////////////////////////////////////////////////////////////////


// Do not edit below this line
var snow=new Array();
var marginbottom;
var marginright;
var timer;
var i_snow=0;
var x_mv=new Array();
var crds=new Array();
var lftrght=new Array();
var browserinfos=navigator.userAgent;
var ie5=document.all&&document.getElementById&&!browserinfos.match(/Opera/);
var ns6=document.getElementById&&!document.all;
var opera=browserinfos.match(/Opera/);
var browserok=ie5||ns6||opera;

function randommaker(range) {
    rand=Math.floor(range*Math.random())
    return rand
}

function initsnow() {
    if (ie5 || opera) {
      marginbottom = document.body.clientHeight
      marginright = document.body.clientWidth
   }
   else if (ns6) {
      marginbottom = window.innerHeight
      marginright = window.innerWidth
   }
    var snowsizerange=snowmaxsize-snowminsize
    for (i=0;i<=snowmax;i++) {
        crds[i] = 0;
        lftrght[i] = Math.random()*15;
        x_mv[i] = 0.03 + Math.random()/10;
        snow[i]=document.getElementById("s"+i)
        snow[i].style.fontFamily=snowtype[randommaker(snowtype.length)]
        snow[i].size=randommaker(snowsizerange)+snowminsize
        snow[i].style.fontSize=snow[i].size
        snow[i].style.color=snowcolor[randommaker(snowcolor.length)]
        snow[i].sink=sinkspeed*snow[i].size/5
        if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
        if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
        if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
        if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
        snow[i].posy=randommaker(2*marginbottom-marginbottom-2*snow[i].size)
        snow[i].style.left=snow[i].posx
        snow[i].style.top=snow[i].posy
    }
    movesnow()
}

function movesnow() {
    for (i=0;i<=snowmax;i++) {
        crds[i] += x_mv[i];
        snow[i].posy+=snow[i].sink
        snow[i].style.left=snow[i].posx+lftrght[i]*Math.sin(crds[i]);
        snow[i].style.top=snow[i].posy

        if (snow[i].posy>=marginbottom-2*snow[i].size || parseInt(snow[i].style.left)>(marginright-3*lftrght[i])){
            if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
            if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
            if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
            if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
            snow[i].posy=0
        }
    }
    var timer=setTimeout("movesnow()",50)
}

for (i=0;i<=snowmax;i++) {
    document.write("<span id='s"+i+"' style='position:absolute;top:-"+snowmaxsize+"'>"+snowletter+"</span>")
}

    window.onload=initsnow;

Answer

got it, you forgot your ‘px’ attribute

snow[i].style.left=snow[i].posx+lftrght[i]*Math.sin(crds[i]) + 'px';
snow[i].style.top=snow[i].posy + 'px';

and in the document write

document.write("<span id='s"+i+"' style='position:absolute;top:-"+snowmaxsize+"px'>"+snowletter+"</span>");

EDIT (full code)

// **** Changed to Hearts from Snow ****

// Set the number of snowflakes (more than 30 - 40 not recommended)
var snowmax=12;

// Set the colors for the snow. Add as many colors as you like
var snowcolor=new Array("#aaaacc","#ddddFF","#ccccDD","#ffffff","#ffc0cb");

// Set the fonts, that create the snowflakes. Add as many fonts as you like
var snowtype=new Array("Arial Black","Arial Narrow","Times","Comic Sans MS");

// **** CHANGE YOUR IMAGE HERE ****

// Set the letter that creates your snowflake (recommended: * )
var snowletter="<img src=images/heart.gif>";

// Set the speed of sinking (recommended values range from 0.3 to 2)
var sinkspeed=0.6;

// Set the maximal-size of your snowflaxes
var snowmaxsize=40;

// Set the minimal-size of your snowflaxes
var snowminsize=20;

// Set the snowing-zone
// Set 1 for all-over-snowing, set 2 for left-side-snowing
// Set 3 for center-snowing, set 4 for right-side-snowing
var snowingzone=1;

///////////////////////////////////////////////////////////////////////////
// CONFIGURATION ENDS HERE
///////////////////////////////////////////////////////////////////////////


// Do not edit below this line
var snow=new Array();
var marginbottom;
var marginright;
var timer;
var i_snow=0;
var x_mv=new Array();
var crds=new Array();
var lftrght=new Array();
var browserinfos=navigator.userAgent;
var ie5=document.all&&document.getElementById&&!browserinfos.match(/Opera/);
var ns6=document.getElementById&&!document.all;
var opera=browserinfos.match(/Opera/);
var browserok=ie5||ns6||opera;

function randommaker(range) {
    rand=Math.floor(range*Math.random())
    return rand
}

function initsnow() {

    if (ie5 || opera) {
      marginbottom = document.body.clientHeight
      marginright = document.body.clientWidth
   }
   else if (ns6) {
      marginbottom = window.innerHeight
      marginright = window.innerWidth
   }


    var snowsizerange=snowmaxsize-snowminsize

    for (i=0;i<=snowmax;i++) {
    crds[i] = 0;
    lftrght[i] = Math.random()*15;
    x_mv[i] = 0.03 + Math.random()/10;
    snow[i]=document.getElementById("s"+i)
    snow[i].style.fontFamily=snowtype[randommaker(snowtype.length)]
    snow[i].size=randommaker(snowsizerange)+snowminsize
    snow[i].style.fontSize=snow[i].size
    snow[i].style.color=snowcolor[randommaker(snowcolor.length)]
    snow[i].sink=sinkspeed*snow[i].size/5
    if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
    if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
    if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
    if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
    snow[i].posy=randommaker(2*marginbottom-marginbottom-2*snow[i].size)
    snow[i].style.left=snow[i].posx
    snow[i].style.top=snow[i].posy
    }


    movesnow()
}

function movesnow() {
    for (i=0;i<=snowmax;i++) {
    crds[i] += x_mv[i];
    snow[i].posy+=snow[i].sink
    snow[i].style.left=snow[i].posx+lftrght[i]*Math.sin(crds[i]) + 'px';
    snow[i].style.top=snow[i].posy + 'px';

    if (snow[i].posy>=marginbottom-2*snow[i].size || parseInt(snow[i].style.left)>(marginright-3*lftrght[i])){
        if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
        if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
        if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
        if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
        snow[i].posy=0
    }
    }
    var timer=setTimeout("movesnow()",50)
}

for (i=0;i<=snowmax;i++) {
    document.write("<span id='s"+i+"' style='position:absolute;top:-"+snowmaxsize+"px'>"+snowletter+"</span>")
}

window.onload=initsnow;