How can I get text from a dialog?

I need to get text from an entry in a dialog, like a login dialog (get the user and password), I've tryied to use 'gtk_entry_get_text' but I did something wrong or there's something else I could use.

In order to get the text from an entry widget in a dialog, you should use gtk_entry_get_text.

char* entry_content;
entry_content = gtk_entry_get_text(GTK_ENTRY(entry_widget));

You should take care of this things:

• First, you should pass the entry widget as a parameter, not the window dialog or other widget.
• You should cast the GtkWidget into a GtkEntry.
• The returning string is allocated by the GtkEntry, so you must not free it.