bhagawatshinde 11 Posting Whiz

Hi,
I have richtextbox control in datagridview Column. i am adding it manually but runtime unable to add in datagridview column it gives me an error like 'PRJNAME.richtextboxcolumn can not converted to system.windows.forms.richtextboxcolumn'
Here i found the Richtextbox contorl
I am add the code like this on form load,

Dim aa As DataGridViewRichTextBoxColumn = New DataGridViewRichTextBoxColumn()
        DataGridView1.Columns.Add(aa)