Button event twice needed - ASAP.....

Hi

I have a button and when it is pressed the following code is executed.

private void btnReplace_Click(object sender, EventArgs e)

{

if (RichTextBoxCntrl.Rtf == "")

{

MessageBox.Show(" Form Content is Empty. Please Select A Form, Click Display Button FIrst ", "Alert");

}

else

{

ContractHeaderMainFieldsReplace();

ContractHeaderPrimeFieldsReplace();

ContractHeaderSubFieldsReplace();

}

Now When i change my selection in a comnbo box and press the button again, the following functions has to be executed.

How to write the event for button press involving both the things to be executed.