javascript - how can make disable if the texts are empty with? -


<?php           echo '<form action="" method="post">         <table cellpadding="5" cellspacing="5">             <tr>                 <td>ad:</td>                 <td><input type="text" name="ad" /><td>             </tr>             <tr>                     <td>soyad:</td>                 <td><input type="text" name="soyad"  /><td>             <tr>                 <td>yas:</td>                 <td><input type="text" name="yas"  /></td>             </tr>             <tr>                 <td>e-mail</td>                 <td><input type="text"e-mail="e-mail"  /></td>             <tr>                 <td></td>                 <td><input type="submit" value="gonder" id="b1"/></td>             </tr>         </table>         </form>';  ?> 

i use ajax send data server. want return false on submit when using ajax. simple solution asking, however, can done follows:

var frm = document.getelementsbytagname('form')[0]; var els = frm.elements; frm.onsubmit = function(){   for(var i=0,l=els.length; i<l; i++){     if(els[i].value === ''){       return false;     }   }   return true; }