The procedure below should build a list of serial numbers of specific parts of speech in the Words dataset. The procedure may have mistakes. Identify all mistakes, if any.
```
1: Procedure BuildList(field)
2: L = {}
3: while (Table 1 has more rows) {
4: Read the first row X in Table 1
5: if (X.PartOfSpeech == field) {
6: L = L ++ [[X.SerialNumber, field]]
7: }
8: Move X to Table 2
9: }
10: return(field)
11: End BuildList
12: L1 = BuildList("Pronoun")
13: L2 = BuildList("Verb")
```