Include variable in javascript

Hello,

I am newbie in javascript, can anyone help me please?

I want to add a variable in: var url
here I want to replace:
var url = "<?php echo $my_variable; ?>";

this variable is used in many pages and for each page have a different name... is not fixed variable.

Thanks in advance for any help !

Regards,
floriano

from JavaScript https://ift.tt/2NY6cJr
via IFTTT