function visa() {
    msgWindow=window.open('','visa','toolbar=no,directories=no,menubar=no,scrollbars=yes,resizable=yes,status=no,width=550,height=400');
            msgWindow.focus();
 }
 
function makeDisable(field) {
    var x=document.getElementById(field)
    x.disabled=true
}
function makeEnable(field) {
    var x=document.getElementById(field)
    x.disabled=false
}

function validate_email(field,alerttxt) {
    with (field) {
        apos=value.indexOf("@")
        dotpos=value.lastIndexOf(".")
        if (apos<1||dotpos-apos<2)
          {alert(alerttxt);return false}
        else {return true}
    }
}

function validate_required(field,alerttxt) {
     with (field) {
        if (value==null||value=="")
          {alert(alerttxt);return false}
        else {return true}
     }
}