Get the id of input on keyup

I have an input box…

<input type="text" id="search_member" onkeyup="lookup(this.value);">

When I type in the field, it will go to function lookup(). From there I want to get the id of this input. I tried…

var This_id = $(this).attr("id");

but this won’t work. Any suggestions on how I can get the id?

Answer

Because you are passing this.value to your lookup() function. It’s better to pass this to your function and then use arg.value to get the value and arg.getAttribute('id') for the id

<input type="text" id="search_member" onkeyup="lookup(this);">

function lookup(arg){
 var id = arg.getAttribute('id');
 var value = arg.value;
 // do your stuff
}