When Do You Use A Semi-colon?

There are various uses that you can have with the symbol of semi-colon but primarily it is used when you want to put some extra information in an statement. The use you can do is to write the statement first and then if you find that some additional information can elaborate the statement, you should use the symbol of semi-colon and then write the statement.
       
You can also use the symbol when you feel that there are too many commas in a sentence and with the use of a number of commas, the sentence does not look good. Sometimes the symbol also serves as super comma when you find that there are a number of sentences that are segregated with the use of comma and in those sentences there formed groups; you can use semicolon to segregate the groups.

That's what we're working on; getting Pro comp to print the color proofs for us