Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Who participated in the Mixed Doubles when Tracey Hallam participated in the Women's Singles?

### Inputs:
table_name: table, columns: ['Year', "Men's singles", "Women's singles", "Women's doubles", 'Mixed doubles']

### Response:
SELECT Mixed doubles FROM table WHERE Women's singles = tracey hallam