SO - 22057911

by Arun P Johny

HTML

<form id="form_a">
    <label>First Name</label>
    <input type="text" class="required" />
    <br/>
    <label>Email</label>
    <input type="text" class="required" />
    <button>Submit</button>
</form>
<form id="form_b">
    <label>Serial No</label>
    <input type="text" class="required" />
    <br/>
    <label>Brand</label>
    <input type="text" class="required" />
    <button>Submit</button>
</form>
<form id="form_c">
    <label>First Name</label>
    <input type="text" class="required" />
    <br/>
    <label>Email</label>
    <input type="text" class="required" />
    <button>Submit</button>
</form>

JavaScript

jQuery(function () {
    $('form').submit(function () {
        var valid = true;
        // whichform is the id so use id selector here
        $(this).find(".required").each(function (i) {
            if ($(this).val().length == 0) {
                alert("null value detected")
                $(this).css("border", "1px solid red")
                valid = false;
            } else {
                $(this).css("border", "")
            }
        });
        //return the valid state
        return valid;
    })
})