Sorting issue

[nagarjuna_kotha]

HI All,

I m facing issue in shorting ,

I m using Calculated Field :::

= if(match(Day([Call log Date]),1,2,3,4,5,6,7),'Week1',

if(match(Day([Call log Date]),8,9,10,11,12,13,14),'Week2',

if(match(Day([Call log Date]),15,16,17,18,19,20,21),'Week3',

if(match(Day([Call log Date]),22,23,24,25,26,27,28),'Week4','Week5'))) )    & '_' &Month  .

If i select More than one month its following Alphabetic Ascending .if select Nov Dec it showing Week1_Dec and Week1_Nov like that i dont want like that.i want Week1_Nov, Week1_Dec like for all as per my secections.

Have a look At screen Shot.                  Its Urgent>>>>>>>>>>

Thanks In Advance