how to add item in a list widget on clicking of a pushbutton

[jyoti]

hi all
my form appears like this(attachment)...
nw i want when i enter any item_name in a line edit and then i click the pushbutton i.e enter item
then that string of line_edit come in list widget box
n even tell me the procedure for remove item(highlightened) from list widget box....

plz do reply as soon as possible..

thanks in advance