find the nearest neighbor in the data set

[robert012345]

Hi Everyone,
First of all,
Happy New Year 2016
Wish all of us have a great year 2016
I have a set of data , usually is about 25000 data points with X,Y coor,
I need to find the nearest neighbor data point , measure the distance and put it into another column,
Hope the attached is clear enough,(I need to find and fill in all yellow cells)
Truly appreciate all your help in this great forum,

Thanks again and best regards,
Robert