Multiple where lexcial parameters (how can i handle this situation?)

Question

hi, I am new to reports can someone help me to solve my problem how can i use multiple lexical parameters for WHERE clause, i am using sample OE (Order Entry) schema
User Parameters
EID_FROM
EID_TO
EID_WHERE_CLAUSE
SAL_FROM
SAL_TO
SAL_WHERE_CLAUSE
QUERY
select EMPLOYEE_ID,FIRST_NAME,LAST_NAME,HIRE_DATE,SALARY,MANAGER_ID,DEPARTMENT_ID
from employees
&EID_WHERE_CLAUSE &Sal_where_clause
AFTER PARAMETER FROM
function AfterPForm return boolean is
begin
if :EID_FROM is NULL or :EID_TO is NULL
     then :EID_WHERE_CLAUSE := 'WHERE 1=1';
ELSE
     :EID_WHERE_CLAUSE := 'WHERE EMPLOYEE_ID BETWEEN '||:EID_FROM||' AND '||:EID_TO;
END IF;     
if :SAL_FROM is Null or :sal_to is Null
     then :SAL_WHERE_CLAUSE := 'WHERE 1=1';
ELSE
     :SAL_WHERE_CLAUSE :='AND SALARY BETWEEN '||:SAL_FROM||' AND '||:SAL_TO;
     END IF;
return (TRUE);
end;

Answer 1

Thank you sir, it really helped me to solve my problem, now it looks like this and working fine, i hope now there is no logical error in my code, please suggest.
i am really surprised by such a rapid response, i hope i will learn soon from GURUZz
PARAMETERS_
EID_FROM
EID_TO
H_DATE_FROM
H_DATE_TO
SAL_FROM
SAL_TO
L_CLAUSE
QUERY_
select e.employee_id, e.first_name, e.hire_date, j.job_title, d.department_name, e.salary
from employees e, jobs j, departments d
where e.job_id = j.job_id
and e.department_id = d.department_id
&L_CLAUSE
order by e.employee_id
AFTERPARAMETERFORM_
function AfterPForm return boolean is
begin
IF :EID_FROM is NULL or :EID_TO is NULL
     THEN NULL;
ELSE
     :L_CLAUSE := 'AND EMPLOYEE_ID BETWEEN :EID_FROM AND :EID_TO';
END IF;
IF :SAL_FROM is NULL OR :SAL_TO IS NULL
     THEN NULL;
ELSE
     :L_CLAUSE := :L_CLAUSE||' AND SALARY BETWEEN :SAL_FROM AND :SAL_TO';
END IF;
IF :H_DATE_FROM is NULL OR :H_DATE_TO IS NULL
     THEN NULL;
ELSE
:L_CLAUSE := :L_CLAUSE||' AND HIRE_DATE BETWEEN ' || '''' || :H_DATE_FROM || '''' || ' and ' ||'''' || :H_DATE_TO || '''';
END IF;
return (TRUE);
end;
Edited by: M. Khurram Khurshid on Jan 4, 2012 8:44 PM