Sharepoint Column Formula

[lvs3594]

Can anyone help am trying to do a formula and have have been succesful for part of it, but the second part isnt working, the full formula I am using is

=IF(OR(ISNUMBER(FIND("AM",Column1)),ISNUMBER(FIND("PM",Column1))),"0,5","Column2"

Basically I am asking if Column 1 contains AM or PM to put the text 0.5 (which works fine), but the part thats not working is that if Column 1 doesnt contain AM or PM then show the existing result in Column 2 (which is another calculated created column with the existing formula in of =DATEDIF([Start Date],[End Date],"d"))

Can anyone help

Thanks

L

[alina]

Here is the link which can be helpful >>>>http://msdn.microsoft.com/en-us/library/bb862071.aspx