Adding Size Of Identified Tables On All Databases On A Servers??

I have used the following script to add the size of chosen tables in all the databases on a given server. What I need to do is to create a GRAND total. Can someone give me a hint?


exec sp_msforeachdb
@Command1 = "print'?'",
@Command2 = "use ?
SELECT CAST (o.name as char(20)) as 'Table', SUM(c.length) 'Record size',
MAX (i.rows) '#of rows',
CONVERT (decimal (10, 4), SUM (c.length * i.rows)/(1024.00 * 1024.00)) 'Approx. size (MB)'

FROM sysobjects o, syscolumns c, sysindexes i
WHERE o.id = c.id
AND o.id = i.id
AND (i.indid = 1 or i.indid = 0)
AND o.type = 'U'
And o.name in ('Table1','Table2','Table3')
GROUP BY o.name
COMPUTE SUM (CONVERT (decimal (10,4), SUM (c.length * i.rows)/(1024.00 * 1024.00)))"

Thank you