textBox1 selectall and focus

Imagine a form with a single text box in it. I handle the onLoad event of the form and I want the the form loads the textbox to have the input focus and the default text in the box to be selected. I tried doing that with textBox1.SelectAll() and textBox1.Focus() but neither of them works as expected( in my app they don't work at all) Can s.b. tell me what am I doing wrong and how to fix it Many thanks in advance, Nikolay