Checkbox in ALV

Hi,

I am using OOPS ALV to display the data. First column of the output is check box. the output is as below.

checkbox Process order item number qty

[] 123 1 23

[] 123 2 20

[] 301 1 15

[] 301 2 10

So in each line i have some data. Now the case is when i have same process order with muliple lines i need to show only check box. means

checkbox Process order item number qty

[] 123 1 23

123 2 20

[] 301 1 15

301 2 10

Can anybody guide me how to achieve this.

Thanks,

Neha