Dear Abid Hussain,
If you are asking me, "what should i do now," I would add to Gianluca's comment that you say in the original post (OP) that you have 4 equations in 4 unknowns. The code has 5 equations in 4 unknowns. I'd suggest that the code be changed to the 4 equations in 4 unknowns you refer to in the OP. I don't know what they are, so I cannot offer any further advice.
