AS3 :: Professional - Place Cursor In Textfield

I am a newbie to actionscript 3.0 and need a litlle help that I have not been able to find searching (for two weeks). I would like the cursor to appear and blink in the first text field in a movie clip that gathers information to be sent to a php. The following  does not work. stage.focus = textField; textField.setSelection textField.text.length,textF ield.text.length);

And the only other things I find are for custom cursors. I just want the visitor to see the blinking cursor in the firstName_txt input box when the page appearss. Also, if the visitor tabs from one input text field to the other, the blinking cursor appears in the first three input text fields but not in the fourth. Yet, the visitor can enter text in the fourth input text field.