How would I have a drop down box menu populate a cll matris worksheet with checkmarks?

I need to develop a calling matrix worksheet. I have the drop down box with a list of different situations and a worksheet with a list of different department names/responsibilities. My confusion is: when I click on a particular issue in the drop down menu I would like the worksheet with all the names to automatically have checkmarks placed under the correct people that must be called for that particular issue. Using Excel 2007
To be more specific, my job is in Emergency response, so when I get a call I can choose the issue from the drop down box and the responsible persons/departments that must be called for that specific issue get a checkmark displayed under their name. I have tried reading "Excel for Dummies" and now feel even "dumber"
Thanks in advance for any help! Sincerely, Thomas
Please find attached Excel workbook...........My incident log matrix.xls

So if an incident is chosen from the dropdown box on Sheet1A5, you want the proper names/contactees to appear on sheet1 rows 6,11 and 16? and these would be retrieved from sheet2 which will have x's or checks in the appropriate cells?

Okay, Not knowing your system, I cannot match up what you have in rows 6,11 and 16 on Sheet1 with what you have in row 1 of sheet 2. I assume for example, G12 (sheet1) under "TSOC (866) 655-7023" would be checked if under the same incident on sheet2 has column Q ("TSOC 866-655-7023") checked. There are 26 catagories to be checked on sheet 2 and only 24 blue boxes on sheet 1.

Here's the easiest way, given what you've told me so far, that I can think of.
On Sheet2, A107 enter
=Sheet1!$A$5
In B107,
=INDEX($B$2:$AA$103,MATCH($A$107,$A$2:$A$103,0),) dragged/copied across to AA107

Then on Sheet1, in each of the notify boxes, enter an IF statement like so. (This one would go in G12)
=IF($Q$107="X", "X","") Match up all the notify cells in sheet1 with what should be checked if they are to be notified on Sheet2. Did this help?

If you have any questions, feel free.

Okay, I used their method of VLOOKUP. I was over complicating things. I formatted the cells with check marks as Marrott. In Marrott, an "a" shows as a checkmark. You'll need that knowledge when you want to put the correct checkmarks in your matrix and that'll help you understand the formulas. Also, the IFERROR Function only works on Excel 2007 and later. Hopefully that's what you have. Is this what you needed?

Marrott is a font type, just like "Ariel", "TimesNewRoman" or "Wingdings" but with specific symbols (like a checkmark). Simply set your font to Marrott instead of Ariel in those cells. I believe the one you are using as a template used Ariel's symbol for a square root. Use whatever checkmark is easiest for you.
You would need to format any cells where you expect a checkmark to appear but no cells where you would want normal text.