text_field_value

Hi,

I have a text_field_value that I want to set the value dynamically, I use this script: $(function() {         $("#keypress").keypress(function() {           alert("from keypress");           $(this).value = "a" ;           return false;         }) })

the alert is shown but the value of the text_field is not changed How can I have the right behaviour (for example every time I press a key, I have the same key twice in the text_field) regards,