There are 5 drop down in my form:

ddl1,ddl2,ddl3,ddl4,ddl5.

ddl1 is mandatory to select rest of them user has to select only one other wise it gives error what i write on my button so that it check if user select values from more then 1 drop down ( in ddl2,3,4,5)it gives error message and reset again all the drop down to blank.

Thanks,

For simplicity and speed, I would instaniate a local variable to keep track of how many ddl's have been selected:

Dim intDdlCnt As Integer

private sub ddlx After_Update()

if intDdlCnt > 1 Then
'reset stuff here
Else
intDdlCnt = intDdlCnt + 1
end if
end sub