In a saucepan, melt butter.  Stir in the flour, garlic powder and pepper until smooth; gradually add milk.  Bring to a boil; cook and stir for 2 minutes or until thickened.  Reduce heat; add cream cheese and parmesean cheese.  Cook and stir for 8-10 minutes or until cheese is melted.  Meanwhile, cook linquine according to package directions.  Add chicken and chilies to cheese sauce; cook 5 minutes longer or until heated through.  Drain linghuine, top with chicken mixture.