function checkInput(theForm) {
	if ((theForm.yname.value==0) && (theForm.yname.value.length<=0)) {
		alert("Ihr Name fehlt !");
		theForm.yname.focus();
		return false
	}

	if ((theForm.company.value==0) && (theForm.company.value.length<=0)) {
		alert("Der Firmenname fehlt !");
		theForm.company.focus();
		return false
	}

	if ((theForm.telephone.value==0) && (theForm.telephone.value.length<=0)) {
		alert("Ihre Telefonnummer fehlt !");
		theForm.telephone.focus();
		return false
	}

	if ((theForm.email.value==0) && (theForm.email.value.length<=0)) {
		alert("Ihre E-Mail fehlt !");
		theForm.email.focus();
		return false
	}
}