document.onkeyup = KeyCheck;       
 
	function KeyCheck(e)
		{
		   var KeyID = (window.event) ? event.keyCode : e.keyCode;
 
		   switch(KeyID)
		   {
 
          // Back
		      case 37:
		        var child = document.getElementById('back');
		        var parent = child.parentNode;             
		        window.location = parent.href;
		      break;
 
          //Forward
          case 39:
		        var child = document.getElementById('forward');
		        var parent = child.parentNode;             
		        window.location = parent.href;
		      break;
		   }
		}