Please, Give me advise about my first line draw program.

[Donggyoo Lee <doogie78 hanmir com>]

Hello. This program is my first GTK+ program.
I want to use GtkWidget not Canvas Widget.

this program compiled well with no error.
but, it does not work. I can't see any line.
I don't know what I miss.
Please, point me about this program's problem. Please.

compile comand:
gcc -Wall -g myline.c -o myline `pkg-config --cflags --libs gtk+-2.0
gdk-2.0`

Thank you,
Donggyoo Lee