E-mail alert based on a field value

Hi,

I am relatively new to using SharePoint. I have a query on using a list.

I've created a list to track certain action items which has many custom columns two of which are "Raised By" and "Assigned To" and both are "Name" fields which are linked to email ids in my organization.

Now, the query is once I give entries to these two fields I would want to trigger e-mails to those IDs. I explored the option of "Alert Me" but that doesnt have provision to do this.

Could someone pls assist me with this?