How do you check to see if a javascript function exits?

[alex.dennis]

i tried checking for document.function_name(), but that apparantly does
not work. Anybody got an answer to this one?

 

[Ivo]

i tried checking for document.function_name(), but that apparantly does
not work. Anybody got an answer to this one?

Using the typeof operator seems to be the simplest way:

if( typeof function_name === 'function' ) {
// function exists, so let's use it
}

hth
ivo
http://4umi.com/web/javascript/

 

[alex.dennis]

thanks, tried it and it works like a charm