Question

This works perfectly in chrome and firefox, and it SHOULD work perfectly in internet explorer.

In fact, if I manually enter a string instead of taking it from the prompt, it works perfectly. The only issue is when I take in the string using ‘prompt’, and as far as I can tell the value I’m getting from that is a string, just like any other!

    value=prompt("extract","youtube code here");
    el=document.getElementById('textarea');
    //matches=value.match(/.*<embed src=(^>*)>.*/gi);
    item=value.split('<embed src=')[1];
    closeTag=item.indexOf('>');
    if(closeTag>-1)
    {
        item=item.substring(0,closeTag);
    }
    alert(item);
    el.value+=item;

Answer 1

Declare your variables and it seems to work for me in IE7:

var value=prompt("extract","youtube code here");
var el=document.getElementById('textarea');
//matches=value.match(/.*<embed src=(^>*)>.*/gi);
var item=value.split('<embed src=')[1];
var closeTag=item.indexOf('>');
if(closeTag>-1)
{
    item=item.substring(0,closeTag);
}
alert(item);
el.value+=item;