Help for Sed Syntax problem

Shell Programming and Scripting
1

I have one File named "txt_file"
# cat txt_file
<DBType>RT</DBType>
<AppType>RT</AppType>
--------------------------------------------------

I want replace "<AppType>RT</AppType>" to
<AppType>XY</AppType> in txt_file and output redirect to Newfile

--------------------------------------------
I have a scipt file named "add.sh"

#cat add.sh
#!/bin/bash
cat txt_file |sed 's'/<AppType>RT</AppType>'/'<AppType>XY</AppType>/'g' >Newfile
___________________________________________

But when I am running that script(add.sh) I am getting error

"add.sh: line 2: AppType: No such file or directory"

It might be syntax problem.

Coul you please help me out.

Thanks in advance!!

Sanjay

2 
sed -e "s+<AppType>RT</AppType>+<AppType>XY</AppType>+g" txt_file >Newfile
3

Perfect Vino Brother !!!
Thanks

Sanjay