Verify element number thats always changing - selenium

Question

How do I write a Selenium IDE command to verify that the number is present if it increases as I invite more people by email??
For example, the total number of people: 30
Example 1: If I invite 1 person, how do I verify that the total number of people is 31?
Example 2: If I invite 5 people, how do I verify that the total number of people is 35?
Here is the code:
<div style="color:#777; font-size:1.3em; float:right; margin-top:5px;">
Total number of people:
<span style="color:red;">30</span>

Answer 1

I believe you would have to:
Store a value for how many invites you are going to do
Store a value for the expected number of people (ie current plus invites)
Go do the invites
Store a value for the new total number of people
Compare the new number to the expected number
The following does the capturing and comparing of the numbers. You just have to add the part for doing the actual invites.
<tr>
<td>store</td>
<td>5</td>
<td>people_invited</td>
</tr>
<tr>
<td>storeText</td>
<td>//div[contains(text(),'Total number of people')]</td>
<td>original_count_text</td>
</tr>
<tr>
<td>storeEval</td>
<td>parseInt(storedVars['original_count_text'].match(/\d+/))+parseInt(storedVars['people_invited'])</td>
<td>expected_count</td>
</tr>
<tr>
<td>echo</td>
<td>Go invite 5 people</td>
<td></td>
</tr>
<tr>
<td>storeText</td>
<td>//div[contains(text(),'Total number of people')]</td>
<td>new_count_text</td>
</tr>
<tr>
<td>storeEval</td>
<td>parseInt(storedVars['new_count_text'].match(/\d+/))</td>
<td>new_count</td>
</tr>
<tr>
<td>verifyExpression</td>
<td>${expected_count}</td>
<td>${new_count}</td>
</tr>