<!-- First checkbox auto fill-->
var res_contactname = "";
var res_phone = "";
var res_fax = "";
var res_email = "";
function InitSaveVariables(form) {
res_contactname = form.res_contactname.value;
res_phone = form.res_phone.value;
res_fax = form.res_fax.value;
res_email = form.res_email.value;
}
function autofill(form) {
if (form.copy.checked) {
InitSaveVariables(form);
form.res_contactname.value = form.acc_contactname.value;
form.res_phone.value = form.acc_phone.value;
form.res_fax.value = form.acc_fax.value;
form.res_email.value = form.acc_email.value;
}
else {
form.res_contactname.value = res_contactname;
form.res_phone.value = res_phone;
form.res_fax.value = res_fax;
form.res_email.value = res_email;
   }
}
<!-- END First checkbox auto fill-->

<!-- Second checkbox auto fill-->
var sale_contactname = "";
var sale_phone = "";
var sale_email = "";
function InitSaveVariables(form) {
sale_contactname = form.sale_contactname.value;
sale_phone = form.sale_phone.value;
sale_email = form.sale_email.value;
}
function autofillparttwo(form) {
if (form.copytwo.checked) {
InitSaveVariables(form);
form.sale_contactname.value = form.res_contactname.value;
form.sale_phone.value = form.res_phone.value;
form.sale_email.value = form.res_email.value;
}
else {
form.sale_contactname.value = sale_contactname;
form.sale_phone.value = sale_phone;
form.sale_email.value = sale_email;
 }
}
<!-- END Second checkbox auto fill-->


<!-- Third checkbox auto fill-->
var mgm_contactname = "";
var mgm_phone = "";
var mgm_email = "";
function InitSaveVariables(form) {
mgm_contactname = form.mgm_contactname.value;
mgm_phone = form.mgm_phone.value;
mgm_email = form.mgm_email.value;
}
function autofillpartthree(form) {
if (form.copythree.checked) {
InitSaveVariables(form);
form.mgm_contactname.value = form.sale_contactname.value;
form.mgm_phone.value = form.sale_phone.value;
form.mgm_email.value = form.sale_email.value;
}
else {
form.mgm_contactname.value = mgm_contactname;
form.mgm_phone.value = mgm_phone;
form.mgm_email.value = mgm_email;
 }
}
<!-- END Second checkbox auto fill-->