[Help-glpk] Mathprogram error rectification

[ashutosh . natraj]

 Hello everybody
 I'm a student at TUD,germany working with Gnu Lpk Mathprogram,its a error in 
the shortest distance between nodes problem in optimization problem,
so i would like to seek your help,if i get some worked out sample ,so that i 
can proceed further in my work,its showing me either literal set error or 
syntax error i hav tried a lot rectifying please help me.
Ashutosh.natraj