How to find source of submit using javascript

Question

Please help me to solve this problem: I have a form in which i have written onSubmit calling a javascript function. please tell me in that javascript function how can i check that who was the event generater ( i mean on which button click this even raised).. Note: onsubmit function call is in form tag.. i am using javascript and asp.net My code is like this:

 <form id="form1" runat="server" onsubmit="return CheckForm()">

    <script type="text/javascript" language="javascript">
        function CheckForm()
            {
            some code here
            } 
    </script>

i dont want to change any functionality.. i have got a dropdownlist which is causing postback.. i want that when this dropdownlist raise post back either i should know that its raised by dropdownlist or that function should not be called by dropdownlist's postback

Answer 1

you can pass this like here is an example...

this.TextBox1.Attributes.Add("onkeypress", "button_click(this,'" + this.Button1.ClientID + "')");

function button_click(objTextBox,objBtnID)
{
    if(window.event.keyCode==13)
    {
        document.getElementById(objBtnID).focus();
        document.getElementById(objBtnID).click();
    }
}

Answer 2

You could add an onclick event to the submit buttons that will set a variable. This value can then be used in the onsubmit event to figure out which button was clicked:

The form:

<form action="" method="get" id="frmOne" onsubmit="return checkVal()">
    <input type="submit" id="btnOne" value="hello01" onclick="testtwo(1)" />
    <input type="submit" id="btnTwo" value="hello02" onclick="testtwo(2)" />
</form>

The script:

<script type="text/javascript">
    var iVal = 0;
    function checkVal() {
        if (iVal == 1) {
            // ... 
            return false;
        } else {
            if (iVal == 2) {
                // ...
                return true;
            }
        }
    }
    function testtwo(val) {
        iVal = val;
    }
</script>

Answer 3

<script type="text/javascript">
   var button=''

   // call this function on button click
   function  clickButtonName(name){
          button=name
   }

   // onSubmit function check for 'button' Variable to find out which event is clicked
don't forget to reset button variable.

</script>

But remember your form is also get sumitted when you are in a textfield inside the form and click on "Enter" button.I think then You have to disable form submission using onkeypress and event class of javascript.