set margin in report.rdlc

 Hai
        In my report.rdlc in page setup I had set the left
margin to .5 and right margin to .2 but when I opens the next report
the setup changes to the default left margin ie, 1 and right margin to
default 1     
How can I assign fixed margins to the reports so that once it is set it wont change when next report is opened
Or is there any way to set margins programatically 

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