How to get the all string names when string starts with "{!" and ends with "}" in the given string.

My code:

<span>Hi {!LastName},Welcome to All. Testttttt character testing.{!LastName1}{!LastName2},{!LastName3},{!LastName4},{!LastName5}{!LastName6},Welcome to All {!!LastName7} </span>

In the above code how to get this all string c ontains    " {!.......}"(it will returs  {!LastName}, {!LastName2}, {!LastName3}, {!LastName4}, {!LastName5}, {!LastName6}, {!LastName7} )

the string contains  {!!LastName} it won't take from string. Then finally I want to calculate the string count except this above " {!.......}: strings.  Is it possible?

Final output string count will put in the "result" span class

My jsfiddle:

http://jsfiddle.net/XzS5V/2/