Random Number generator and verification problem

[jinnah]

In one of the fileds data needs to be between 10-99 and unique.
For now I am trying the following codes

Code:

Dim upperbound, lowerbound
upperbound=99  
lowerbound =10
For i=10 to 99  
CatEventCode=Int((upperbound - lowerbound + 1) * Rnd + lowerbound)  
Next[/b][/color]

[color=#800000][b]If Browser("...").Page("...").WebEdit("...").GetROProperty("value")=CatEventCode Then
    Reporter.ReportEvent micPass,"2 digits value is entered in <CAT/EvenetCode> field",""
    Call Logger(1," 2 digits value is entered in <CAT/EvenetCode> field")
    else
    Reporter.ReportEvent micFail,"2 digits value is not entered in <CAT/EvenetCode> field",""
    Call Logger(2,"2 digits value is not entered in <CAT/EvenetCode> field")
End If

Why does verification fail?

Any other idea for generating 2 digits unique number?