How to access camunda cam-variable-name value of one form to another

Hi, I have created external forms i.e .html files and in that I am using one common jQuery for validation of field and that Js file is external file and I am using in every html files as external js file like below

How can i make one form cam-variable as value of another form field ?
or
how can i access these cam-variable in my js file on load of another form.?

can anyone please help me