string with single quotes in query and query fails with ORA-00923: FROM keyword not found where expe

Hi gurus,

I have a query


select &name ,& desig from dual;
ORA-00923: FROM keyword not found where expected


and &name and &desig comes from a package in global variables

and valiables  &name  and &desig values are 'Test'ing'  and  'Querys'  respectively
 with the values query is formed/looks like

select 'Test'ing' , 'Querys' from dual;

this query fails with ORA-00923: FROM keyword not found where expected .

Please provide your inputs how to handle strings which has single quotes in sting while running a sql statement where the values are dynamicaaly passed to variables and variables are substituted in sql query.