prime

// Returns if a number is prime or not
var Divisor;

// Loop through all divisible values of the number
for(Divisor = 2; Divisor <= floor(sqrt(argument0)); Divisor += 1;)
{
    // See if the number is divisible by the divisor
    if(argument0 mod Divisor == 0)
    {
        // Return the number this is divisible by
        return Divisor;
    }
}

// This number is prime
return 1;