Just to complete the above comment:

You should also check if your text fields are empty then you are passing null values to database,use db.null value:
eg:
If faxnumber.Text = "" then
    oComm.Parameters("@fax_number").Value = DBNULL.value
Else
    oComm.Parameters("@fax_number").Value = faxnumber.Text
End If

Thanks to every one that reeplies to this this topic.
Thanks In Advance.
YoOrD.

Beauty Is not in the face
Beauty is In the heart
--<<Ghibran Khalil>>--