expanding the x-axis dynamically

I have charts in which x-axis displays the name of the agents as per the records in db. Now what happens is sometimes i have only 3-4 records the hart displays well but when I have more than 10 or 15 records the x-axis skips to display the name of some of the agents. How can I fix this issue? Like the chart should be able to accommodate the necessary changes expand or shrink depending on the amount of data and the problem is solely with the x-axis.

Thanks in advance,
Megha