javascript

hi all,

i need to read the field or get it's value from the business process 

i am trying using javascript i tried multiple choices but they did no sense

i tried :

Xrm.Page.data.entity.attributes.get('header_process_new_sitevisitdate').getValue()

Xrm.Page.getAttribute('header_process_new_sitevisitdate').getValue()

Xrm.Page.getControl('header_process_new_sitevisitdate').getValue()

Xrm.Page.getControl('new_sitevisitdate').getValue

known that the field name is "new_sitevisitdate"

thanks