function validiere_form() {
    var error_string = "Bitte füllen Sie alle erforderlichen\nEingabefelder aus!\n";
    var error_check = false;
    var sel_el;

    for(var i=0; i < document.forms.length; i++) {
        var tform = document.forms[i];
        for(var j = 0; j < tform.elements.length; j++) {
            if( typeof tform.elements[j].onblur == "function" ) {
                var f = tform.elements[j].onblur;
                var fs = f.toString();
                if( fs.indexOf('nichtleer',fs) >= 0) {
                    if( tform.elements[j].value.toString().length == 0 ) {
                        if(error_check == false) sel_el = tform.elements[j];
                        error_check = true;
                    }
                }
            }
        }
    }

    if(error_check) {
        alert(error_string);
        sel_el.focus();
        return(false);
    } else {
        return(true);
    }
}

function nichtleer() {
	return (true);
}