look up field from another table

look up field from another table

hi i have two forms

Form name -->category

fileds are name,DELETED


Form2----->task
with look up filed task_category from form1

Now i want to display only those categories where DELETED =0
i AM USING THIS BUT ERROR SAYS NO FILED deleted in category


clear task_category;
for each xx in category [category.DELETED == 0]
{
task_category.add(xx.name);
}