function checkfield(Form,feldname,Text,nofocus){
    var fehler = "";
    for(i=0;i<document.forms[0].length;++i){
        if(document.forms[0].elements[i].name == feldname){
            if (document.forms[Form].elements[i].value == ""){
                fehler =  Text;
                if(nofocus == null){
                   document.forms[Form].elements[i].focus();
                }
            }
        }
    }
    return fehler;
}