SETFOCUS

This function will set the focus to any control on your form which has a valid TAG value.

SETFOCUS(tag)

PARAMETERS

tag

The TAG value of one of the controls on your form. 

EXAMPLE:
Assuming that you have two Textboxes on your form, one with a TAG value of FIELD1 and another with a TAG value of FIELD2, you could perform the following operation:

SETFOCUS(FIELD1)

This would set the focus to the FIELD1 textbox