step by step debugging for Addins in Outlook 2003 and C#

[Mallikarjun S Bendigeri]

Hi,
Iam building a Add-in for Outlook. On Clicking a button on CommandbarPopup( created programmitically), I display a windows form. The windows form has a datagrid populated with data from XML file. First time When I click the commandbarbutton on the Commandbarpopup, the form is loaded and displayed.
When I close the form and again clicked the commandbarbutton on Commandbarpopup (for Second time) the form does not appear.
I have written MessageBox.show in the Click event to find if the Event is fired.
First time it is fired second time it is not.
How can do the step by step debugging to check what is the errorHere is the code in the
private void oPopupButton_Click(CommandBarButton Ctrl, ref bool Cancel)
{
MessageBox.Show("Popup");
try
{
if (frm1 ==null)
frm1=new frmShowPhoneList();
frm1.Show()=true;
}
catch(System.Exception ex)
MessageBox.Show(ex.Message);
}