There's not any one code for anything. That's like asking for the word that describes the story of some novel. There are a million ways to tell that story. Just think about the things that go into it.
First, we need to know where the mouse is:
Second, we need to know where this clickable area is:
LowX=100 : HighX=300
LowY=100 : HighY=150
Of course, these values can be what ever you want them to be.
Third, we need to know if the mouse is within this area:
if mx>=LowX and mx<=HighX and my>=LowY and my<=HighY
`Something goes here
endif
Next, we need to know if the user is clicking while inside this area:
if mx>=LowX and mx<=HighX and my>=LowY and my<=HighY and mouseclick()
`Something goes here
endif
And finally, we need the protected code inside the
if block to actually do something. Tell it to display the next screen or tell it to go somewhere else that will display the next screen with
goto.
Whenever you have problems, just break them down into pieces. It's the way to get better and learn.