convert rows to CSV, see http://stackoverflow.com/questions/20609952/create-a-csv-from-a-variable-length-newline-input

csv.awk

EGIN {
    FIELD_LIST = "Field1,Field2,Field3"; # fields definition, in order
    split(FIELD_LIST, fields, ",");
}

{
    pos = find(fields, $1);
    if (pos == 0) {
        print("unexpected field " $1);
        exit 1;
    }
    if ($1 == fields[1] && NR>1) { # record start
        echo_record(fields, rec);
        split("", rec)
    }
    rec[$1] = $2; # store field value
}
END {
    echo_record(fields, rec);
}

# find position of val in arr. 0 if not found
function find(arr, val)
{
    i=1;
    for (idx in arr) {
        if (arr[idx] == val) return i;
        ++i;
    }
    return 0;
}

function echo_record(fileds, record)
{
    start = 0
    for (key in fields) {
        if (start) printf(", ");
        start = 1;
        val = record[fields[key]];
        if (val) printf("%s", val);
        else printf(" ");
    }
    printf("\n");
}