function clearText(thefield){
if (thefield.defaultValue==thefield.value)
thefield.value = ""
}

 function check(){
 var nameValue =document.mailform.Name_Vorname.value;
 var mailValue = document.mailform.EMail.value;
 var nummerValue = document.mailform.Nummer.value;
  
 if(nameValue == 'Name, Vorname'){
     document.getElementById("mailformName_Vorname").value = "";
     }
 if(nummerValue == 'Telefon'){
     document.getElementById("mailformNummer").value = "";
     }
 if(mailValue == 'E-Mail'){
     document.getElementById("mailformEMail").value = "";
     }
	if(validateForm('mailform','Name_Vorname,Name%2C%20Vorname,Nummer,Nummer','','','')){
		return true;
	}else{
		return false;
	}
 }