Ok, now the only error I'm getting is this.

C:\Documents and Settings\root\Desktop\exploit.c: line 7: too many locals declared
'char contenido[10000], cookie[91]="a%3A2%3A%7Bs%3A11%3A%22autologinid%22%3Bs%3A0 %3A%22%22%3Bs%3A6%3A%22userid%22%3Bs%3A1%3A%22", cookief[9]="%22%3B%7D", cookiec[106], cookie_false[92]="a%3A2%3A%7Bs%3A11%3A%22autologinid%22%3Bb %3A1%3Bs%3A6%3A%22userid%22%3Bs%3A1%3A%222%22%3B%7D", *pos'
aborting compile

What to do about that?