Line Chart With Grid and Rounded Edges of Canvas

[Line Chart With Grid and Rounded Edges of Canvas]

Hello Friends,

 

 Am Working on Chart Application for Producing Statics of Data in Line, Bar and Pie Chart. 

 

 I Have Problem for Line Chart, i Want to Make Canvas Border of Line Chart As Rounded Corner,

 

 how can i do it . . . 

 

 i used following code for making rounded rectange on graph but when data changes it collapse

 

 

<annotations>

<annotationGroup id="Grp1" showBelow="1">

<annotation type="rectangle" x="60" y="48" toX="785" toY="365 " radius="10" color="000000" fillAlpha="100" showBorder="1" fillColor="ffffff" borderColor="000000" borderThickness="3"/>

</annotationGroup>

</annotations>

 

 

please look at screen shot for more details , and suggest me solution . .