$viewer
if { [string compare "$viewer" "v2d"] == 0 } {
    2dclear
    donly result
    2dfit
} elseif { [string compare "$viewer" "smallview"] == 0 } {
    clear
    donly result
    fit
} else {
    puts "Error : wrong value of variable viewer"
}
xwd $imagedir/${test_image}.png

# to end a test script
puts "TEST COMPLETED"