string_base64_encode
This function returns the base64 representation of a string.
string string_base64_encode(string the_string)
Parameters:
the_string
The string that will be encoded.
Return value:
A string containing the base64 representation of the given string on success, or an empty string on error.
Remarks:
Base64 is a way in which to represent binary data in a textual format. This means that the NULL character, ASCII code 0, will never be present in a base64 encoded string and it may therefore be used to store binary data in situations where only text content is supported. Converting binary data to a hexadecimal representation accomplishes the same thing, but base64 encoded strings are shorter than hexadecimal strings and are thus more suitable when space is an issue.
Example:

    void main()
    {
    string original=input_box("Enter string", "Enter the string to convert to base64.");
    alert("Original", original);
    string encoded=string_base64_encode(original);
    alert("Encoded", encoded);
    string decoded=string_base64_decode(encoded);
    alert("Decoded", decoded);
    }