Dynamically Add Update Parameter To Formview

I have a formview with name, email, and password.  I bind all fields to sql except the password which is blank.

In my sqldatasource, I define parameters for name, email and id:

UpdateCommand="UPDATE UserProfile SET Name = @Name,Email = @Email WHERE (ID = @ID)">
<UpdateParameters>
<asp:Parameter Name="Name" />
<asp:Parameter Name="Email" />
<asp:Parameter Name="ID" />
</UpdateParameters>

In code I want to add a password parameter if there is value in the password field otherwise I don't want the password field updated.  If I add define a password parameter like above then if a user left the password field blank then their new is blank.  That's way I think adding it dynamically is the way.  But I am having problems with the code to add the parameter in sqldatasource_updating event.

Protected Sub SqlProfile_Updating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.SqlDataSourceCommandEventArgs) Handles SqlProfile.Updating
Dim password As TextBox = FormView1.FindControl Protected Sub SqlProfile_Updating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.SqlDataSourceCommandEventArgs) Handles SqlProfile.Updating
Dim password As TextBox = FormView1.FindControl("tb_password1")
If Not password.Text.ToString & "" = "" Then
SqlProfile.UpdateParameters.Add(New Parameter("@Password", TypeCode.String, password.Text.ToString))
End If

End Sub Thanks