CBOT - reading hex string

int hexval(string s)
{
    int a = 0;
    s = strupper(s);
    while(s != "") {
        string x = strleft(s, 1);
        s = strright(s, strlen(s)-1);
        int n = strval(x);
        if(x == "A") n = 10;
        if(x == "B") n = 11;
        if(x == "C") n = 12;
        if(x == "D") n = 13;
        if(x == "E") n = 14;
        if(x == "F") n = 15;
        a = a * 16 + n;
    }
    return a;
}

extern void object::New()
{

    string s = "303132";
    while(s != "") {
        int x = hexval(strleft(s, 2));
        s = strright(s, strlen(s)-2);
        message(x);
    }
}