Excel rearrange data using excel

[azranaim]

hi,

I have a lot of data and i have to rearrange data from A to B such as below using excel. I did manually using filter the id no and copy paste the marks for each of the id no, but it takes a lot of times to solve this problem. Can anybody help me??

A) original data
id_no marks
88662 47
97271 54
97271 56
97271 54
97271 87
97271 30
99216 38
99754 21
99754 99
99791 81

B) new data
id_no marks
88662 47
97271 54 56 54 87 30
99216 38
99754 21 99
99791 81