Expression switch facility

Hello, I would ask about the possibility of implementing a switch algorithm via expressions in Reporting services to . For example, Can I test on the dataset field a

if a= null -->display none

if a= 1 -->display "string1"

if a= 2 -->display "string2"

some help about this topic

thanks in advance

= Switch(Fields!a.Value = 1, "string1", Fields!a.Value = 2, "string2", Not(Fields!a.Value), "", true, "else string here")