you didn't say what your problem. try this to check whether given number is a Prime Number

Option Explicit
Public Function IsPrime(ByVal n As Long) As Boolean
Dim I As Long
IsPrime = False
If n <> 2 And (n And 1) = 0 Then Exit Function 'test if div 2
If n <> 3 And n Mod 3 = 0 Then Exit Function 'test if div 3
For I = 6 To Sqr(n) Step 6
If n Mod (I - 1) = 0 Then Exit Function
If n Mod (I + 1) = 0 Then Exit Function
Next I
IsPrime = True
End Function

thanks for your response dear but its showing compile error "invalid inside procedure"
sorry for incomplete description actually i need a program to print prime numbers from 1 to 100
i am working in vb6. and putting this coding in command button on click event, please check and reply.

actually i have made a program which is creating all of the non-prime numbers from 1 to 100 but i am unable to compare it... and generate prime numbers...

this is the program

Private Sub Command1_Click()
Dim o As Integer
Dim z As Integer
Dim y As Integer
Dim x As Integer
Dim W As Integer
Dim a(114) As Integer
o = 0
For z = 2 To 50
o = o + 1
a(o) = z * 2
Next z
For y = 2 To 33
o = o + 1
a(o) = y * 3
Next y
For x = 2 To 20
o = o + 1
a(o) = x * 5
Next x
For W = 2 To 14
o = o + 1
a(o) = W * 7
Next W
End Sub

Hello!
My question is how to code search in combobox each time typeing a letter. And the search result in DropDown have to show list items which contains letter or ...