Empty Function Paramaters

How do i declare a default value in a function? I have a simple function

[CODE]
function color_input(id,token){

if (!empty(token)){
document.getElementById(id).style.backgroundColor = ‘#2A2A2A’;
document.getElementById(id).style.color = ‘#DDC58C’;
}else{
document.getElementById(id).style.backgroundColor = ”;
document.getElementById(id).style.color = ”;
}

}
[/CODE]

Called in HTML like

[code=html]<input type=”text” id=”example_name” onblur=”color_input(‘example_name’);”>[/code]

You will notice that the #2 parameter is missing in the html call. Sometimes i don’t have it to send. in PHP i would just set the functions second param like token=”

[CODE]function color_input(id,token=”){}[/CODE]

How do i set a default param in a JS function?

Also in #JavaScript _↴