I've been looking for this for while, and sharing is carying !
So there is the code I figured from few samples on net. Hope this will help someone !
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim groupName As String = InputBox("enter group name")
If ListView1.FindItemWithText(groupName).Text = groupName Then
MsgBox(groupName & " already exists")