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 onclick="return validate('form_a')">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 onclick="return validate('form_b')">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 onclick="return validate('form_c')">Submit</button>
</form>

JavaScript

function validate(whichform) {
    var valid = true;
    // whichform is the id so use id selector here
    $('#' + whichform + " .required").each(function (i) {
        if ($(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;
}