strval_

strval_(const string[])
{
    new
        l = strlen(string),
        val;

    if(l > 10)
        return 0;

    for(new i = l - 1, m = 1; i >= 0; i--, m*=10)
    {
        if(!('0' <= string[i] <= '9'))
            return 0;

        new
            s_val = (string[i]-48)*m;

        if(cellmax - val < s_val)
            return 0;

        val += s_val;
    }

    return val;
}