Convert the Text of Textbox in Upper case

Good Day

I am placing a textbox on my page  to take any word as input

and I want that whenever a user press any alphabet whether in upper case or lower case it gets converted in upper case..

I use following code in TextChanged(object sender, TextChangedEventArgs e) Method 

tbx_Word.Text = tbx_Word.Text.ToUpper();

But it moves the control at 0 position each time I type any alphabet..

Please suggest some other way..

Thank You.. 

sunaina