How can get control ID when it is within UpdatePanel, and original its visible is false?

Question

Hi All, If someone could help me on the following? I have a master page with update panel, on this master page there are 2 conrol (all are inside updatepanel): 1)ucTitle -- a label will display title from db, and edit button next to it 2)ucEditTitle -- a txtBox and save button, visible= false Once user clicks edit button, ucTitle becomes not visible and ucEditTitle will be visible Now on one of my pages, I need to get that txtBox id because my task is to warn the user if inputs bad word. This can be accomplished by ScriptManager.RegisterStartupScript(this, this.GetType(), "myscript", strScript, true); however I cannot get that control's id, it is not included in source (via view source) I tried made the ucEditTitle visible to true, then view source I can see the txtBox id; but once I set the visible to false at master page, even at Edit mode I cannot see ucEditTitle at all. Thank you for your time. Ellen