data = getenv("QUERY_STRING");
    
    if(data == NULL)
        printf("<P>Error! Error in passing data from form to script.");
    else
        if(sscanf(data,"maq_1=%s&maq_2=%s",&maq_1, &maq_2)!=2)
            printf("<P>Error! Invalid data. Data must be numeric.");
        else
            printf("<P>%s %s.",&maq_1,&maq_2);