How to concatnate value to text box

Hi Friends
  private void savedata1(string type, object Sender, EventArgs e)
    {
        System.Globalization.DateTimeFormatInfo dateinfo = new System.Globalization.DateTimeFormatInfo();
        dateinfo.ShortDatePattern = "MM/dd/yy";
        Objen = new SowidEn();
        Objen.CITI_SOWID = txtSowid.Text.ToString() + 'V' + 0.1;
}
This is my save method when i click on save button every clcik need to generate new versiovalue just like
 Textbox value is 1000  after one click
it  needs to show 1000v0.1
second click needs to
1000v0.2,1000v0.3....
Please help me
 
 
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