[Skipp]

Вроде так:

<label>Model:&nbsp;
	                <select id="sls" name="option[19][value]" onchange="sc()">
	                    <option value="hdd1000,70.00">HDD 1000GB</option>
	                    <option value="hdd500,60.00">HDD 500GB</option>
	                    <option value="hdd250,50.00">HDD 250GB</option>
	                </select>
	            </label>
	                &nbsp;<a id="link" href="info/hdd_1000gb.html" rel="facebox"><img alt="Information" border="0" src="images/i.png" /></a>&nbsp;
					
				<script type="text/javascript">
					function sc()
					{
						var opt = document.getElementById('sls').getElementsByTagName('option');
						for(var i=0; i<opt.length; i++)
							if(opt[i].selected)
								document.getElementById('link').setAttribute('href', "info/" + opt[i].innerHTML.replace(" ", "_") + ".html");
					}
				</script>