// Register behaviours here
var myrules = {
	'img.popup' : function( element ) {
		element.onclick = function(){
			popUp( this.src.replace( /(\.jpg|\.gif|\.png)/i, "_big$1" ), this.alt );
		}
	}
};
	
Behaviour.register( myrules );

function popUp( url, alt ) {
	var new_win = window.open( "/popup.asp?url=" + escape( url ) + "&alt=" + escape( alt ), "popup", 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=1,width=533,height=400,left=340,top=312');
	new_win.focus();
}