generating Unique ID from textboxs on userform

hi all

i have to text boxes "Reg1" (says either ("normal", "Sick", "Training") and "Reg3" (Date) and one spare "Reg24" and a button called Generate ID

what i would like is a marco that looks at text in Reg1 and Reg2 then looks at Col F on a sheet called Database (for previous ID's so not to return a duplicate)

and then the whole thing returns a unique ID.

i dont even know if this is possible but could anyone help in this quest please

unique ID to be created before all information from user form gets put onto sheet2 "Database"

i dont know if this code will help in the quest and can me modified in any way

=IF(C3="","",LEFT(D3,1)&LEFT(C3,1)&RIGHT($Z$3,4)+1)