i know this a stupid question, but i don't why this code isn't working:

fct = JOptionPane.showInputDialog("enter a string");
JOptionPane.showMessageDialog(null,fct,"info",JOptionPane.INFORMATION_MESSAGE);
if (fct == "abc")
JOptionPane.showMessageDialog(null,"OK","info",JOptionPane.INFORMATION_MESSAGE);

plz help, i'm new in java