Private Sub cmdLeftRight_Click(ByVal sender As System.Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles cmdLeftRight.Click, cmdCenterRight.Click, cmdCenterLeft.Click, cmdRightLeft.Click<BR> <BR> Dim sourcePane As String = CType(sender, ImageButton).Attributes("sourcepane")<BR> Dim targetPane As String = CType(sender, ImageButton).Attributes("targetpane")<BR> Dim sourceBox As ListBox = CType(Page.FindControl(sourcePane), ListBox)<BR> Dim targetBox As ListBox = CType(Page.FindControl(targetPane), ListBox)<BR><BR>end sub<BR><BR><BR>why i can not find my control with the "Page.FindControl" method?<BR>the string name is correcte, the control exist on my page. I still have that error "object reference not set to an instance of..object"<BR><BR>what do i do wrong here !!<BR><BR>thanx