want to find accession number in osirix then show their count of result using applescript

code is as

set a to field "Accession_Number" of table "RIS_PatientRegisteration_Mst" of database "RIS" as text

tell application "Finder"

Tell Application "Osirix" to activate

end tell

tell application "System Events"

tell process "OsiriX"

Try

tell menu bar item "File" of menu bar 1

click

tell menu item "search" of menu "File" to click

end tell

end try

set b to 0

keystroke a

set b to count Studies ----this is the line where i want to show no. of records of osirix---------

say b

if b exists then

say "anjali found"

else

say "not Found record ok"

end if

end tell

end tell