I have a Problem with a tab control to display the next tabpage when the user presses the button

LT Bebeza

You did not provide much information! Which button? Just set the TabControls SelectedIndex property if you want to change the TabPage.

Jacob.

Just get the current tab index, store it in an integer, increment the integer by 1, and reset the selectedIndex:

(Visual C++.Net)
int x = tabControl1->SelectedIndex;
tabControl1->SelectedIndex = x+1;

Place this under a button_Click event, and the next Tabpage will be displayed.