Rowspan in gridview for second column

hi friends

               In gridview i have repeted row values in both first and second columns i have to merge those

repeted values into single cell(Rowspan).

(i have merged cells of first column at the same time i cant merge the second column.)

 for example

 Column1                 column2       

Alexandria                       NSW
Coffs Harbour                   NSW
Darlinghurst                   & ...