javascript验证

Question

this is the scenario, I have this form HTML

<form class="mainForm" name="eform" id="eform" action="/itg/sc_cust_maint_pkg.cust_dml"         method="get">
<div id="tab1" class="tab_content">
<div class="rowElem noborder"><label>Customer ID:</label>
<div class="formRight240">
<input type="text" name="p_cust_id_c" id="req" class="validate[required,maxSize[30]]"/>
</div></span><div class="fix"></div>

What I have to do is validate the required input, and add asterisk to the label,the working mode is to fix the problems using what we have, so I have to find a solution using just this. the million question is, how to validate if p_cust_id_c is required using that class, and once do that then add an asterisk to the label.

Answer 1

Get the elements, check if the inputs class contains the string required , then add something to the label ?

var form  = document.getElementById('eform');
var input = document.getElementById('req');
var label = form.getElementsByTagName('label')[0];

if (input.className.indexOf('required') != -1) {
    label.innerHTML = label.innerHTML + '***';
}

FIDDLE