Fernando,

In the GotFocus() of your subclass you will have to:

TextBox::GotFocus()
nodefault
this.SelStart = 6

Without the NODEFAULT the default behavior of the VFP baseclass will undo your setting of the SelStart after your overridden code executes.

>I try to do this (Make a subclass of the TextBox Class, and type the code to get the behavior that I want).
>
>I call the new subclass MyTBox. The MyTBox.gotfocus() is {this.selstart=6}
>
>In the dessigner form, I add MyTBox control to the form. Also I add a grid.
>The Grid has 2 column. I remove the default textbox of the column2 and add the new MyTBox class to the column2.
>...But the I get behavior in the 2 MyTbox (MyForm.MyTBox), but not in the Form.Grid1.Column2.MyTBox.
>
>Where is the problem?