Factorial Recursive Algorithm

Code
// Factorial RecursionAlgorithm(A combination of N numbers)
Function Calfactorial (N)
{
If (N <   0 )
{
Return   ' N cannot be negative. ' ;
}
Else   If (N =   0 )
{
Return   1 ;
}
Else
{
Return N * Calfactorial (n -   1 );
}
}

Function Factorialwork (anumber, recursnumber ){
// Recursnumber keeps track of the number of iterations so far.
If (Anumber =   0 ){ // If the number is 0, its factorial is 1.
Return   1 .;
} Else {
If (Recursnumber >   100 ){
Return ( " Too many levels of recursion. " );
} Else { // Otherwise, recurse again.
Return (Anumber * Factorialwork (anumber -   1 , Recursnumber +   1 ));
}
}
}

Function Factorial (anumber ){
// Use Type annotation to only accept numbers coercible to integers.
// Double is used for the return type to allow very large numbers to be returned.
If (Anumber <   0 ){
Return ( " Cannot take the factorial of a negative number. " );
} Else { // Call the recursive function.
Return Factorialwork (anumber, 0 );
}
}

//Call the factorial function for two values.
Alert (factorial (5));
Alert (factorial (80));