Changing FCK Text Value at runtime

Can anyone teach me how to change the text value inside a FCKeditor instance?

im using ASP.net but i wanted to change text value using javascript when a button is pressed.
how do i go about doing that?




<fckeditorv2:fckeditor id="fckEdit" basepath="~/fckeditor/" runat="server"
toolbarset="Basic"></fckeditorv2:fckeditor>

<asp:Button ID="Button1" runat="server" Text="Button"
onClientClick="alert('I NEed TO change the text value here');"/>

Ineed to change the text value on the alert script.