validation - Javascript Validation in Joomla Component

Question

      <script language="javascript">

function myValidate(f) {
        if (document.formvalidator.isValid(f)) {
            f.task.value='save';
            f.submit(); 
        }
        else {
                alert('Error!');
                return false;
        }
        return false;
}
</script>

Putting form action as : : below

<form action="index.php" onsubmit="return myValidate(this);" class="form-validate" method="post" name="adminForm" id="adminForm">

Its working on this comment submit button very fine, not on save & Close in joomla

<!--<input type="submit" name="submit" id="submit" value="submit" />
-->
<input type="hidden" name="option" value="com_result" />
<input type="hidden" name="id" value="<?php echo $this->result->id; ?>" />
<input type="hidden" name="task" value="" />
<input type="hidden" name="controller" value="result10" />

Not working in Joomla Component.Saving the form On Ok Button of Error Alert. any suggestion ?