facing problem in "optimtool"

i got two small programs named "obj.m" and "nlc.m" i need to find solution using optimtool window.....obj.m is the objective function,nlc.m is the constraint,i am using interior point algorithm,i have given my start points......when i push the start button a message displayed as below......what changes i need to make to get the optimized answer.

Optimization running.

Undefined function or method 'obj.m' for input arguments of type 'double'.