i want to cascade the serial interrupt in my program like

the micro controller should recieve one RI and move to the specific case. in the case statement it must wait for the other to respond accordingly

i am writing the program like this

while(1)
{
if(RI)

m=SBUF

switch(m)
{
case'1':
RI=0;
if(RI)
{
P1=SBUF;
}
case '2':'
----
.
.
.
.
.
}

but this is not working
plz suggest how can i nest the if statement for RI


regards
uzmeed