userform autogenerate charaters in the textbox

[aimjhun]

hi guys, i need your help, i have a problem with my userform, i want in my add contact person form if i want to select sponsor name from the drop down menu which is linked in my members name sheet i want that i will automatically generate its members id into the members card no. textbox. without typing the no. thanks in advance. hope you can help me with my problem. im still a newbie on this one. i really much appreciate you help. please see attached file.thanks