// Check for valid email address: look for @ and .
function isEmail(elm) {
    if (elm.value.indexOf("@") != "-1" &&
        elm.value.indexOf(".") != "-1") {
        return true;
    }
    else {
        return false;
    }
}

// check for integer
function isInt(elm) {
    if (elm.value == "") {
        return false;
    }
    for (var i = 0; i < elm.value.length; i++) {
        if (elm.value.charAt(i) < "0" || elm.value.charAt(i) > "9") {
            return false;
        }
    }
    return true;
}

// Check for blank fields
function isFilled(elm) {
    if (elm.value == "" || elm.value == null) {
        return false;
    }
    else {
        return true;
    }
}

// Check selectlist
function isSelected(elm) {
    if (elm.selectedIndex == 0) {
        return false;
    }
    else {
        return true;
    }
}

// Check checkbox
function isChecked(elm) {
    if (elm.checked == false) {
        return false;
    }
    else {
        return true;
    }
}

// Show Error
function showErr(errmsg) {
        var layer = document.getElementById(errmsg);
        layer.style.display='block';
        //layer.style.visibility = "visible";
}
// Hide Error
function hideErr(errmsg) {
        var layer = document.getElementById(errmsg);
        layer.style.display='none';
        //layer.style.visibility = "hidden";
}

// Check entire form
function bookingVal(form) {

    if (isFilled(form.name) == false) {        // full name
        //alert("Please enter your name.");
        showErr("name_err");
 		form.name.focus();      
        return false;
    }
    else {
    	hideErr("name_err");
    }

    if (isEmail(form.email) == false) {          // email address
        //alert("Please enter a valid email address.");
        showErr("email_err");
        form.email.focus();
        return false;
    }
    else {
    	hideErr("email_err");
    }
    
    if (isFilled(form.tel) == false) {          // phone number
        //alert("Please enter a telephone number. Numeric characters only.");
        showErr("tel_err");
        form.tel.focus();
        return false;
    }
    else {
    	hideErr("tel_err");
    }
  
	if (isSelected(form.vehicle) == false) {         // vehicle type
        //alert("Please enter a message.");
        showErr("vehicle_err");
        form.vehicle.focus();
        return false;
    }
    else {
    	hideErr("vehicle_err");
    }
    
	if (isSelected(form.service) == false) {         // service type
        //alert("Please enter a message.");
        showErr("service_err");
        form.service.focus();
        return false;
    }
    else {
    	hideErr("service_err");
    }

    return true;
}