function chkloginform(frm) {
 var elm
 elm = frm.DigipassSerial
 with (frm)
{
 if (((elm.value == null) || (elm.value == "")))
 {
 alert("Het veld is niet gevuld");
 return false;
 }
 else if ((/\D/.test(elm.value)))
 {
 alert("Het veld mag alleen cijfers bevatten");
 return false;
 }
 else
 {
 action = 'https://www.snsregiobank.nl/secure/bankieren/scripts/login/cvb_part/index1.asp';
 target = '_new';
 method = 'post';
 return true;
 }
 }
}

function checkLogIn() {
 if (chkloginform(document.formulier)) {
 document.formulier.submit();
 }
}