Ignore the confrontational advice above.
Assemble your reasons for deserving a pay rise.
If you have had good evaluations over the years, or achieved some target, made economies, provided sound solutions, yada yada.
Don't rely on the unfairness of being paid less than others (sets you up for the answer 'theyr'e worth more') although use that too if there are no good reasons why you should be paid less.

Drinks on you when you get the pay rise.
( Larry Vest One day at a time, sweet Jesus, FFS., Wed 22 Jul 2009, 11:56, Reply)