Question

I have used javascript to add this when a particular page get loaded.

document.getElementById('commit').addEventListener("click", validateSubmit,
                      false);

this validateSubmit method have some code which will validate form data and
it will do this

      function validateSubmit(){
           //some code
           window.addEventListener('submit', newsubmit, true);
           HTMLFormElement.prototype._submit = HTMLFormElement.prototype.submit;
           HTMLFormElement.prototype.submit = newsubmit;
       }

       function newsubmit(event) {
           var target = event ? event.target : this;
           event.preventDefault();
           return false;

        }

so for the first time while submitting form by clicking its coming in this method and it is preventing form values to submit and after fixing al those values when i am again trying to click on submit button then its not working,in console i am getting this error-

      "Uncaught TypeError: Cannot call method 'preventDefault' of undefined"

Please help me…
Thanks in advance..

Answer 1

I don’t think you need to go through such pains to prevent user from submitting incomplete form. Try this:

<form name="form1" id="form1" onsubmit="return validateForm()" ....>
   <input type="text" id="txtName" />
</form>

function validateForm()
{
    //CHECK IF FORM FIELDS CONTAIN VALID VALUES?
    var formValid=....;//validation logic

    return formValid;
}

Now if during validation you find any error you will set formValid variable to false otherwise if all input is correct set formValid to true. When form will getfalseas return value fromvalidateForm` function it will not submit.