Jquery form, disable submit button until required field entered [closed]

Answer 1

Loop through the form fields and check if there is any field/s still left out empty, if yes keep disabled submit button, else enable submit button.

var flag = true;

$('#yourFormID').each(function() 
   {  
       if($(this).val() == "")  
       { 
             /* $('input[type="submit"]').attr('disabled'); may be you will need this if you are checking form on every form element*/
              flag = false;
       }
   }
if(flag) {
        $('input[type="submit"]').removeAttr('disabled');
}

I will suggest to call this code on on last element of your form