Topic: send the cursor back to a missed field

I want to pop a message and then send the cursor back to the missed field if the user move the cursor to click the submit button before the form is completed

I can popup the message with on mouse enter
but how do I put the cursor back in the correct field?

It is a text field where I am trying to place the cursor - I would love it if I could turn the background or edge of the text filed red to indicate what is missing.

Re: send the cursor back to a missed field

You can set focus for control, example: 
Form1.Edit1.SetFocus;


Also you can change backgroung color of TextBox:
Form1.Edit1.Color := clRed;


but don't forget after that return default color, for example in the event of the form OnClose
Form1.Edit1.Color := clWindow;

Dmitry.