guarda se vai con tasto destro sulla pagin e fai visualizza codice sorgente ti visualizza tutto i css e i js..... la fortuna dei programmi lato client e questo che è anche la sfortuna dei programmatore poiche a copiare il codice nn ci vuole molto...
questo e il codice della funzione che dici te in questo modo
codice:
<select name="project_type" id="or" onchange="populate(this)">
	<option value="">Choose One...</option>
        <option value="Web Design">Web Design</option>
        <option value="Web App Design">Web App Design</option>
	<option value="Print Design">Print Design</option>
	<option value="Logo Identity">Logo Identity</option>
        <option value="Idea Bouncer">Idea Bouncer</option>

	<option value="Media Creation">Media Creation</option>
	<option value="Just Saying Hi">Just Saying Hi</option>
</select> 

<select name="budget" id="de">
       <option value="">&larr; Choose Project...</option>
</select> 

<select name="timeline">
        <option value="">Choose One...</option>
	<option value="2 Months">Within 2 Months</option>
	<option value="4 Months">Within 4 Months</option>
	<option value="6 Months">Within 6 Months</option>
	<option value="Whenever">Whenever</option>

        <option value="None">None</option>
</select>
il codicejs e questo
codice:
<script type="text/javascript">
		function populate(o)
		{
			d=document.getElementById('de');
			if(!d){return;}			
			var mitems=new Array();
                        mitems['Idea Bouncer']=['$250 per hour'];
			mitems['Web Design']=['$7,500 - $10,000','$10,000 - $15,000','$15,000 - $20,000','$25,000 - $50,000','$50,000 - $100,000','$100,000+'];
                        mitems['Web App Design']=['$15,000 - $20,000','$25,000 - $50,000','$50,000 - $100,000','$100,000+'];
			mitems['Print Design']=['$1,000','$2,000','$3,000','$5,000+'];
			mitems['Logo Identity']=['$2,000','$3,000','$5,000+'];
			mitems['Media Creation']=['$1,500','$3,000','$5,000+'];
                        mitems['Just Saying Hi']=['Dudes, your website is kick-awesome!','I might be stalking you...','What is up?','Showing some love.'];

			d.options.length=0;
			cur=mitems[o.options[o.selectedIndex].value];
			if(!cur){return;}
			d.options.length=cur.length;
			for(var i=0;i<cur.length;i++)
			{
				d.options[i].text=cur[i];
				d.options[i].value=cur[i];
			}
		}
    </script>