What should i put in the set and what should my condition be?

Compute the income tax due on a taxable income entered by the user. Be sure to include error checking to make sure the user does not enter a negative number. theres a chart as well

http://ift.tt/241GxPA

What's making me stuck is what should be my condition,am i declaring the right thing and what should be the set? i have declare incometax, taxdue, as float

call input

call set

call output

input

write " enter taxable income"

input taxable income

end input

set

i dont know.

output

help me