Show that $2(\sin y + 1)(\cos y + 1) = (\sin y + \cos y + 1)^2$ The question states:

Show that: $$2(\sin y + 1)(\cos y + 1) = (\sin y + \cos y + 1)^2$$

This is what I have done 
$2(\sin y + 1)(\cos y + 1) = 2(\sin y + \cos y + 1)^2$
L. H. S.                = R. H. S.
From L. H. S.
$2(\sin y +1)(\cos y + 1) = 2(\sin y\cos y + \sin y + \cos y + 1)$
$= 2(\sin y\cos y + \sin y + \cos y + \sin^2 y + \cos^2 y)  (\sin^2 y + \cos^2 y = 1)$
$= 2(\sin^2 y + \sin y\cos y + \sin y + \cos^2 y + \cos y)$
I got stuck here. I do not know what to do from here. 
I have tried and tried several days even contacted friends but all to no avail.

$$RHS - LHS=(\sin y + \cos y + 1)^2-2(\sin y + 1)(\cos y + 1) $$
$$=[(\sin y +1)+( \cos y + 1) -1]^2-2(\sin y + 1)(\cos y + 1) $$
$$=(\sin y +1)^2+( \cos y + 1)^2 + 1 -2(\sin y + 1)-2(\cos y + 1) $$
$$=[(\sin y +1)^2-2(\sin y + 1)+1]+[( \cos y + 1)^2 - 2(\cos y + 1)+1] -1 $$
$$=\sin^2 y+\cos^2 y -1  = 0$$
