function changeclass(id,cl) {
	el = document.getElementById(id);
	el.className = cl;
}
function IsNumeric(strString)
   //  check for valid numeric strings	
   {
   var strValidChars = "0123456789.-";
   var strChar;
   var blnResult = true;

   if (strString.length == 0) return false;

   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++)
      {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
         {
         blnResult = false;
         }
      }
   return blnResult;
   }
function validim(tf) {
	msg='';
	if(tf.selArtist.options[tf.selArtist.selectedIndex].value==-1) { msg=msg+('\n - artist');}
	if(tf.selCategory.options[tf.selCategory.selectedIndex].value==-1) { msg=msg+'\n - category';}
	if(tf.selCategory.options[tf.selMedium.selectedIndex].value==-1) { msg=msg+'\n - medium';}
	if(tf.selCategory.options[tf.selPeriod.selectedIndex].value==-1) { msg=msg+'\n - period';}
	if(tf.selCategory.options[tf.selSubject.selectedIndex].value==-1) { msg=msg+'\n - subject';}
	if(tf.txtTitle.value=='') { msg=msg+'\n - title';}
	if(tf.txtPrice.value=='') { msg=msg+'\n - price';}
	if(IsNumeric(tf.txtPrice.value)==false) {msg=msg+'\n - price must be a number';}
	if (msg!='') {
		alert('The following fields must be completed\n'+msg);
		return false;
	}
	return true;
}
function sniffBrowsers() {
	var ns4 = document.layers;
	var op5 = (navigator.userAgent.indexOf("Opera 5")!=-1) 
		||(navigator.userAgent.indexOf("Opera/5")!=-1);
	var op6 = (navigator.userAgent.indexOf("Opera 6")!=-1) 
		||(navigator.userAgent.indexOf("Opera/6")!=-1);
	var agt=navigator.userAgent.toLowerCase();
	var mac = (agt.indexOf("mac")!=-1);
	var ie = (agt.indexOf("msie") != -1); 
	var mac_ie = mac && ie;
}
function getElementHeight(Elem) {
	var ns4 = document.layers;
	var op5 = (navigator.userAgent.indexOf("Opera 5")!=-1) 
		||(navigator.userAgent.indexOf("Opera/5")!=-1);
	var op6 = (navigator.userAgent.indexOf("Opera 6")!=-1) 
		||(navigator.userAgent.indexOf("Opera/6")!=-1);
	var agt=navigator.userAgent.toLowerCase();
	var mac = (agt.indexOf("mac")!=-1);
	var ie = (agt.indexOf("msie") != -1); 
	var mac_ie = mac && ie;
	if (ns4) {
		var elem = getObjNN4(document, Elem);
		return elem.clip.height;
	} else {
		if(document.getElementById) {
			var elem = document.getElementById(Elem);
		} else if (document.all){
			var elem = document.all[Elem];
		}
		if (op5) { 
			xPos = elem.style.pixelHeight;
		} else {
			xPos = elem.offsetHeight;
		}
		return xPos;
	} 
}

function getElementWidth(Elem) {
	var ns4 = document.layers;
	var op5 = (navigator.userAgent.indexOf("Opera 5")!=-1) 
		||(navigator.userAgent.indexOf("Opera/5")!=-1);
	var op6 = (navigator.userAgent.indexOf("Opera 6")!=-1) 
		||(navigator.userAgent.indexOf("Opera/6")!=-1);
	var agt=navigator.userAgent.toLowerCase();
	var mac = (agt.indexOf("mac")!=-1);
	var ie = (agt.indexOf("msie") != -1); 
	var mac_ie = mac && ie;
	if (ns4) {
		var elem = getObjNN4(document, Elem);
		return elem.clip.width;
	} else {
		if(document.getElementById) {
			var elem = document.getElementById(Elem);
		} else if (document.all){
			var elem = document.all[Elem];
		}
		if (op5) {
			xPos = elem.style.pixelWidth;
		} else {
			xPos = elem.offsetWidth;
		}
		return xPos;
	}
}
function getImageWidth(myImage) {
	var x, obj;
	if (document.layers) {
		var img = getImage(myImage);
		return img.width;
	} else {
		return getElementWidth(myImage);
	}
	return -1;
}

function getImageHeight(myImage) {
	var y, obj;
	if (document.layers) {
		var img = getImage(myImage);
		return img.height;
	} else {
		return getElementHeight(myImage);
	}
	return -1;
}
function getRef(obj){
	return (typeof obj == "string") ?
		document.getElementById(obj) : obj;
}
function setStyle(obj,style,value){
	getRef(obj).style[style]= value;
}
function compareheights(im1,im2) {
	if (getImageHeight(im1)>getImageHeight(im2)) {
		var pad=(getImageHeight(im1)-getImageHeight(im2))+'px';
		i1 = document.getElementById(im2);
		i1.style.paddingBottom=pad;
	}	
	if (getImageHeight(im2)>getImageHeight(im1)) {
		var pad=(getImageHeight(im2)-getImageHeight(im1))+'px';
		i1 = document.getElementById(im1);
		i1.style.paddingBottom=pad;
	}	
}

function MM_jumpMenu(targ,selObj,restore){ //v3.0
  eval(targ+".location='"+selObj.options[selObj.selectedIndex].value+"'");
  if (restore) selObj.selectedIndex=0;
}