后面的代码清除了updatepanel文本框后未调用Javascript

Question

I a web page that creates a note in a text area, On first time page load everything works fine. Meaning it goes and does a post back and writes to a database. Now , without reloading the page, on a second try if i change a drop down value and try to write to database it will not write a duplicate entry based on my code which is fine and i will clear out the note created in the text area (which is in an update panel) but for the next consecutive time if i change the drop down value, a java script that actually creates a note in the text area will not get fired and simply the text area is blank. Any help is appreciated.

   <asp:UpdatePanel> 
         <asp:TextBox ID="txtGenVVOE" name= "txtGenVVOE"  TextMode="MultiLine"
                                                runat="server"  style="font-size:  11px" rows="4" cols="44" Width="324px"></asp:TextBox></td></tr>
         <tr>  <td valign="top" align="center" width="50%"> 
  <asp:Button ID="btnCopy"
    class="btn"  runat="server" onmouseover="this.className='btn btnhov'"
                                onmouseout="this.className='btn'" style="background: silvergradient"   Text="COPY"
     OnClientClick="ClipBoard();return false;"
           ToolTip="Copy Text to ClipBoard"  />      /td></tr> <end update Panel>

I have a .js script to create the note called validate() which validates the fields before creating the note

function validate() {

create_note() // which creates a note based on all the fields on the form. }

So, as i have mentioned, this function validate is on button_click OnClientClick event and does not get called when button is clicked without reloading the page. I need some help in understanding why the scripts gets called only once on load and not on subsequent time after an postback is done to an update panel. Thanks in advance.

Answer 1

You will want to re-register the script in the code behind using ClientScript.RegisterStartUpScript ( http://msdn.microsoft.com/en-us/library/z9h4dk8y.aspx )

In the code that causes the postback you would want to do something like this:

Dim script as string = "<script type=""text/javascript"">validate();</script>"
ClientScript.RegisterStartupScript(me,me.gettype(),"NameYourScript",script,false)

If RegisterStartupScript doesn't hit try RegisterClientScriptBlock ( http://msdn.microsoft.com/en-us/library/btf44dc9.aspx )

I can't remember which one gives me trouble when it comes to update panels.