Transfer user entered/LOV value to model dialog page and its title

I have a main report page(Page 1) where it has several LOV based parameter fields user use to apply to the underline report. It also has several button where each will pointing to a different model dialog page. What I what  is to transfer the use chosen value on the report page and apply their value to those model dialog page, the dialog page title also need to change dynamically based on the user chosen values. 
Here is how to do it:

1.  Create a hide item P1_DIALOG_TITLE, this will hold the value of the dialog title
2. On the report page(page 1),  create DA based on change of these parameter values, put three true actions:
 
    a. PL/SQL action, put 'null;' in the plsql.  This is to submit the user chosen values for those parameter
    b. put follow javascript into the second true action:
    3. Refresh the report action

var header_str
if ($v("P1_MONTH")!='') {
header_str='Billing Month:'+$v("P1_MONTH");
}
else {
header_str='Billing Month: Current Month';
}
if ($v("P1_BU")!='') {
header_str=header_str+" BU:"+$v("P1_BU");
}
if ($v("P1_BC")!='') {
header_str=header_str+' BC:'+$v("P1_BC");
}
if ($v("P1_RC")!='') {
header_str=header_str+' RC:'+$v("P1_RC");
}

$s('P1_DIALOG_TITLE',header_str)

In this case, I have 4 parameters: MONTH/BU/BC/RC

3. In the dialog page, apply the needed parameters to the sql section.
4. in the dialog page, put this in the Attribute of the page
   
   title: XXXX + $v('P1_DIALOG_TITLE')

Here XXX can be different title for different dialog page

Note. the dialog page will be able to share the same item from the Mail Page. I didn't realized this in the beginning, instead, I created separate hide items on the dialog page and tried to use the set value to carrier them over but that doesn't work

That's IT