Expecting Statement but saw block

[seblon]

...
on (release) {
    if (clickTAG.substr(0,5) == "http:") {
        getURL(clickTAG);
    }
}
...

Problem at line 10 character 13: Missing semicolon.
on (release) {
Problem at line 10 character 14: Expected to see a statement and instead saw a block.
on (release) {

Ich hoffe jemand weiss was da falsch ist.
Danke schonmal im Vorraus.

 

[Frank]

fehlt vor dem on nicht ein function?

function on(release) {
  alert("do something")
}