//*** This code is copyright 2003 by Gavin Kistner, gavin@refinery.com
//*** It is covered under the license viewable at http://phrogz.net/JS/_ReuseLicense.txt
//*** Reuse or modification is free provided you abide by the terms of that license.
//*** (Including the first two lines above in your source code satisfies the conditions.)



// Find an ancestor element of 'el' with the correct tagName
// and/or where a certain attribute equals the supplied value
function Ancestor(el,tagName,attr,value){
	if (tagName) tagName=tagName.toLowerCase();
	while (el){
		if((!tagName || (el.tagName && tagName==el.tagName.toLowerCase())) && (!attr || (typeof(el.getAttribute)=='function' && el.getAttribute(attr)==value))) return el;
		el=el.parentNode;
	}
	return null;
}



// examples:
// var myParentTable = Ancestor(this,'table');
// var selectedParent = Ancestor(this,null,'className','selected');
// var insideAValidatingForm = Ancestor(this,'form','autoValidate','true');


// Version 1.5 ... now with even less incorrect slop!