Auto populate text to textbox from drop down menu.

hi sir, hope you are good.

i need your help in acrobat for,

in my form,

i have a Drop down box with 5 options (Person1, person2,.... person5)  and a text box.

i want to auto populate text to text box from drop down box.

ex: if drop down box.selected item"Person1" then

textbox1.text="Shekhar"

else if