Can you tell me how to take a value from a JavaScript file and send it to a PHP file?

Code:

```
var year      = (year != null) ? year : '".$this->arrToday["year"]."';

var month     = (month != null) ? month : '".$this->ConvertToDecimal($this>arrToday["mon"])."';

var day       = (day != null) ? day : '".$this->arrToday["mday"]."';

my_window= window.open ('Event.php','mywindow1','status=1,width=350,height=150'); 

\\

```

I want to send the variables (year,Month,day) to Event.php. 

Can you tell me how?