ok here it is.....
DIM ht1 as new hashtable
Dim datarow1 As DataRow
DIM strName as string
DIM intID as integer
FOR EACH datarow1 IN dt1.Rows
strName=datarow1(0)
intID=datarow(1)
IF ht.contains(strName)
ht(strName) = ht(StrName) & "," & intID
ELSE
ht(StrName)="{" & intID
END IF
NEXT
ht(StrName)= & "}"
' Now the hash table has what you want ....
http://www.learnasp.com/freebook/learn/hashtable.aspx
shows you most of what you need to know about hashtable.