i know that break clause is working fine if i want to come out from loop,but if i want to come out from loop what can i use?thanks in advance.

let me give you reply my self so if any one new comer comes he can understand after searching on net i used it and it works perfectly here example for it ,u can use exit for to come out from for loop and exit while to come put from while loop.

eg.
 For j = 66 To 90
            i = i + 1
            c = Convert.ToChar(j)
            If i = 25 Then
                Exit For
            End If
            ch(ar) = c.ToString()
            ar = ar + 1

        Next j