FormView replace empty string in textbox before insert

Hi,
How can I replace empty space in textbox with a dash (-) before form values are inserted?
protected void FormView1_ItemInserting(object sender, FormViewInsertEventArgs e) { TextBox txbPageName = FormView1.FindControl("txbPageName") as TextBox; txbPageName.Text = txbPageName.Text.Replace(" ", "-"); }

I also tried using the datasource's Inserting method but neither works.
Any ideas?
Thanks

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