Question

function clickButton(e, buttonid)         
            var evt = e ? e : window.event;
            var bt = document.getElementById(buttonid);
            if (bt) {
                if (evt.keyCode == 13) {
                    bt.click();                                                  
                    return false;
                }
            }
        }

txtChatMessage.Attributes.Add("onkeypress", "return clickButton(event,'" + btnSendChat.ClientID + "')");

this function is an attribute that is set in code behind file. How do I reset the text in textbox after the button click fires

Answer 1

You can do it like this, by passing the text field from code behind using this, and setting its value to empty string in javascript

In code behind

txtChatMessage.Attributes.Add("onkeypress", "return clickButton(this, event,'" + btnSendChat.ClientID + "')");

In javascript

function clickButton(txt, e, buttonid){
   var evt = e ? e : window.event;
   var bt = document.getElementById(buttonid);
   if (bt) {
        if (evt.keyCode == 13) {
             bt.click();    
             txt.value = "";                                               
             return false;
   }

The above code will over write the existing value of text box. To save it for later use we can use hidden field

In html

<asp:hidden id="hdnText" runat="server" >

In javascript

function clickButton(txt, e, buttonid){
   var evt = e ? e : window.event;
   var bt = document.getElementById(buttonid);
   if (bt) {
        if (evt.keyCode == 13) {
             bt.click();    
             document.getElementById('<%= hdnText.ClientID %>').value = txt.value;                                               
             return false;
   }

In Code behind

Send text field to javascript function

txtChatMessage.Attributes.Add("onkeypress", "return clickButton(this, event,'" + btnSendChat.ClientID + "')");

Get value of textbox from hidden field

string textBoxValue = hdnText.Value;