I'm trying to get a sum only if 2 conditions are met.

Column A has dates (ex. 01/02/2007) in a random order. Column B has a location in a text format (ex. London). Column C has a series of values formatted as [h]:mm.

What I'm trying to do is get a sum of the values in column C where the corresponding values in columns A and B = the date and loction I specify. I've tried...

=SUM(IF(('Jan ''07'!A$2:A$750="1/2/2007")*('Jan ''07' E$2:E$750="London"),'Jan ''07'!J$2:J$750))

but it's returning zero values regardless of the criteria being met or not. Any suggestions ?