The purpose of below to load the form with the data without page submit but the below approach didn't work.
Form - initialization begin put on AJAX CALLBACK point as follow
Then i called it from JavaScript DA on button.
Following apex cod used.
But it is not initializing the data on form when button pressed.
apex.server.process('APEX',{pageItems : '#P1_EMPLOYEID'},
{
dataType : 'text', success : function(data)
{
if(data != 'SUCCESS') apex.message.alert(data);
}
}
)