how to execute mail command in a shellscript
 

pls tell me how to excute mail command in shell script

i had given mail -s "hello raj" raj in shell,
where raj is username
but when i execute that script cursor is wainting for input until i press cntrl+d

But i have to send mail to a user in a shellscript not from the prompt

Have the body of the letter in a file
will send a mail with body.txt as body of the letter and
subject as Hello raj