title: Array Objects and Datagrid with Link Button (Clear Button) in Adobe Flex
body: <p>I have an an array of objects. I populate the datagrid from the array. The nmber of columns in the datagrid is fix i.e.5 and the first column always shows serial number (0,1,2,3,4).
  I have a link button called 'CLEAR' in the last column of the datagrid. </p>
  
  <p>1> How do I make the clear button visible only when the row is particularly clicked ?</p>
  
  <p>2> When the clear button is clicked,  how do I make the contents of that particular row cleared. Not deleted, only cleared to insert data again. Also, the serial number (0,1,2,3,4) should not be cleared, nor deleted. How to do this  ?</p>