[jQuery] How can I overwrite a var ?

[jQuery] How can I overwrite a var ?


Can I overwrite a var outside of an event function?
var myVar = 0;
function firstFun() {
// some ajax call here
success: function(data) {
$("select #myOption").change(function(){
     myVar = 1; // set new value
secondFun()
})
}
}
function secondFun() {
alert(myVar) // instead of 1 I get 0.
}