Mark this is the code i am using to validate wether the person has access to the form or not if he has no access then it will goto the last if case. I am getting the program error when the person has no access if a person has access then i am not getting the program error.
first the no access message comes when i click the ok button of the message box after that i am getting program error messgage.

************************Code from Here mark Thank you Very Much*********
local modCode, sGroup, sMod, GroupCodeLocator, mAccessString
IF TYPE("mDataPath") <> "C"
DO "SetPath"
ENDIF
IF TYPE("gVersion") <> "C"
PUBLIC gVersion
gVersion = "PMIS"
ENDIF


IF TYPE("mAccess")<>"C"
PUBLIC mAccess
mAccess =";"+this.securitygroup+LOWER(this.securitymod)+";"
ENDIF
set step on

IF NOT EMPTY(gUser)
modCode = This.SecurityMod
sGroup =this.securitygroup
sMod =this.securitymod
* BY PASS IF Group and Mod are "X"
IF sGroup = "X"
mViewType ='EDIT'
ELSE
* CHECK IF THERE IS A ; AT THE END OF THE ACCESS
IF LEN(mAccess)<>RAT(";",mAccess)
mAccess = mAccess+";"
ENDIF
mViewType = "NOACCESS"
* check for group access ie change control, submittals,utilities
GroupCodeLocator = AT(";"+sGroup,mAccess)
IF GroupCodeLocator >= 1
* separate out the access for this group
mAccessString = SUBSTR(mAccess,GroupCodeLocator+2)
mAccessString = SUBSTR(mAccessString,1,AT(";",mAccessString) -1)
DO CASE
CASE LOWER(sMod)$mAccessString && EDIT ACCESS
mViewType = "EDIT"
thisform.setaccess
OTHERWISE && NO ACCESS
mViewType = "NOACCESS"
ENDCASE
ENDIF
ENDIF
ELSE
ENDIF
IF mViewType='NOACCESS'
=MESSAGEBOX("You do not have access to this Module.",48)
RETURN .F.
ENDIF