function doSearch ( s ) {
	var regExp1 = /\bfield\b/; //used to test for reserved word field in query string
	var regExp2 = /[(,),<,>,\[,\]]/; //used to test for reserved char(s) in the query string
	var str = s.value;
	if ( str == "" ){
		alert("U dient iets in te vullen in het zoekveld.");
		s.focus();
	} else {
			if ( typeof regExp1.source != 'undefined' ) //supports regular expression testing
			if ( regExp1.test( str ) || regExp2.test( str ) ){
					var alrt = "Please note that you can not include:";
					alrt += "\n\nThe reserved word 'field'\nthe characters [, ], (, ), < or >";
					alrt += "\n\nin your search query!\n\nIf you are confident that you know";
					alrt += "\nwhat you are doing, then you can\nmanually produce the URL required."
					s.focus();
					return alert( alrt );
			}
			document.location = "/nwohome.nsf/pages/zoekresultaat?opendocument&subfrm=search&query=" + escape( str );
	}
}