function newImage(arg) {
	 if (document.images) {
	  rslt = new Image();
	  rslt.src = arg;
	  return rslt;
	 }
	}
	
	function changeImages() {
	 if (document.images && (preloadFlag == true)) {
	  for (var i=0; i<changeImages.arguments.length; i+=2) {
	   document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
	  }
	 }
	}
	
	var preloadFlag = false;
	function preloadImages() {
	 if (document.images) {
	  viscom_12_over = newImage("gfx/viscom_12-over.gif");
	  viscom_13_over = newImage("gfx/viscom_13-over.gif");
	  viscom_14_over = newImage("gfx/viscom_14-over.gif");
	  viscom_15_over = newImage("gfx/viscom_15-over.gif");
	  viscom_15_over = newImage("gfx/button_on.gif");
	  preloadFlag = true;
	 }
	}
	function searchValidate(src) {
	 if (src.Keyword.value=='') { 
	   alert('Please enter a keyword.');
	   src.Keyword.focus(); 
	   return false;
	 } else { 
	   return true;
	 }
	}
	document.onload = preloadImages();