Blocks are Rendering Wrong

OpenGL OpenGL: Basic Coding
1

Hello

I am trying to display blocks on the screen, but it complete renders wrong.

This is my code: OUTPUT: http://i.imgur.com/jv5xR.pngimport org.lwjgl.opengl.GL11;import or - Pastebin.com

And the output is as following:

792×592 17 KB

Does anyone know why this happens?

Thanks.