document.onkeyup = KeyCheck;       
	
	function KeyCheck(e)
		{
		   var KeyID = (window.event) ? event.keyCode : e.keyCode;
		   var prev_link = document.getElementById('prev_image');
		   var next_link = document.getElementById('next_image'); 
		
		   if ((prev_link != null) && (KeyID == 37)) window.location = prev_link.getElementsByTagName('a')[0].href;
		   else if ((next_link != null) && (KeyID == 39)) window.location = next_link.getElementsByTagName('a')[0].href;
		   
		}