How to exexute a script for all Global datatable iterations, when the script is set to run for only one iteration in QTP

''To Declare the  variable”
Dim i,icount
''To Get the Globalsheet object”
Set Global=Datatable.GlobalSheet
''To take the values in rows”
icount=Global.GetRowCount
For i=1to icount
''To Set value in the current row”
Global.SetCurrentRow i
''To Execute the code that to be repeated here” 
msgbox Datatable("Username")
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