Generate Unique Component ID

After I create a page, I need my default component in the page to generate a unique ID and display it.

I have read a lot of threads related to this. UUID is something I could use and below code also i could use

f(F.P1.AUTO_NUM.rawValue == null)

{

var d = new Date();

var code = d.getDay().toString() + d.getMonth().toString() + d.getFullYear().toString() + d.getHours().toString() + d.getMinutes().toString() + d.getSeconds().toString() + d.getMilliseconds().toString();

//Set to code the the text field

F.P1.AUTO_NUM.rawValue = code;

}

I could not understand where to add his code or create a servlet or how could I create component with UUID property, Please Help.