function validateForm(myForm) {
    if (myForm == null)
        return false;

    //Loop through the form and validate
    for (var i = 0; i < myForm.length; i++) {
        var curElem = myForm.elements[i];
        if (curElem.getAttribute("req") == "true") {
            if (curElem.value == "") {
                curElem.focus();
        alert(curElem.name + " is missing");
                return false;
            }
        }
        if (curElem.getAttribute("email") == "true") {
            var address = curElem.value;
            var check = (address.indexOf(".") > 2) && (address.indexOf("@") > 0);
            if (check != "1") {
                alert ("email format is wrong");
                return false;
            }
        }
        if (curElem.getAttribute("num") == "true") {
            if (isNaN(curElem.value)) {
                curElem.focus();
                curElem.select();
                alert(curElem.name + " must be a number");
                return false;
            }
            if (curElem.value < 0) {
                curElem.focus();
                curElem.select();
                alert(curElem.name + " must be a positive number");
                return false;
            }
        if (curElem.getAttribute("nummin")  != null) {
                if ( (curElem.value-0) < (curElem.getAttribute("nummin")-0) ) {
                    curElem.focus();
                    curElem.select();
                    alert(curElem.name + " must be greater or equal to " + curElem.getAttribute("nummin") );
                    return false;
                }

            }
            if (curElem.getAttribute("nummax")  != null) {
                if ( (curElem.value-0) > (curElem.getAttribute("nummax")-0) ) {
                    curElem.focus();
                    curElem.select();
                    alert(curElem.name + " must be smaller or equal to " + curElem.getAttribute("nummax"));
                    return false;
            }
            }
        }
    }

    return true;
}