Substantive procedures to obtain evidence in relation to revenue of a company

I want to ask whether the following substantive procedures to obtain audit evidence in relation to revenue of a company are valid:
1. For a sample of good despatch notes, ensure that the corresponding records are in the sales ledger (test the completeness).
2. For a sample of sales recored in the sale ledger , vouch to the good despatch notes to examine the evidence of good despatch (test the existence).