The Code/s Which Will Set the Internal Osc. to 4MHz for PIC16F628

Good day,

Could you please help me with the code/s which will set the internal Osc. to 4MHz for a PIC16F628.

I used the following for a external Crystal for 4MHz.

Device = 16F628( pic16f628 pdf (http://www.kynix.com/uploadfiles/pdf8798/pic16f628-042fp_200619.pdf) )

Xtal = 4

All_Digital = True

Dim D As Word

Int: TRISB = %00000000

PORTB = 0

D = 150

Main: High PORTB.0

DelayMS D

Low PORTB.0

GoTo Main

Now I would like to use the internal Osc. to do the same as the external Osc.

Thanks very much