Close The Form Unless The User Adds Text In Txtprojend?

I have a Save() function as shown below;

Code:
Public Function Save() As Boolean
Dim valid As Boolean = True
Dim Message As String = String.Empty

[Code].....

What I want to do is when The toolbarbutton1 is clicked it checks for the
Save () - if txtprojend.Text = "" then it displays the message. So far, it does that but then it closes the form. I don't want it to close the form unless the user adds text in txtprojend, as it is a mandatory field.