hey guys i have a problem to make a message box on my VB 6.0

if you see there i have make a command button that if i fill it with an ID that i have make before i can input the time when i push the button but i want to make a message box that if i haven't input the correct ID or i let the text box empty give a notice that i have to put the correct pasword

i have try but always find a debug with my coding
help me please