//*** This code is copyright 2003 by Gavin Kistner, !@phrogz.net
//*** 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 && ((tagName && (!el.tagName || tagName!=el.tagName.toLowerCase())) || (attr && (typeof(el.getAttribute)!='function' || el.getAttribute(attr)!=value)))) el=el.parentNode;
	return el;
}


// 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!