Struts.xml vs. struts.xml

I am new to Struts2 and I am working on a simple project that helps me to learn. I started with my Struts.xml file with the S capitalized. When I run it, I get my web page as expected with a couple fields and a submit button. When I fill them in and click submit, I get a 404 error saying:

There is no Action mapped for namespace [/] and action name [MyAction] associated with context path [/MyProject]  

I did some research and found a suggestion to change Struts.xml to struts.xml just by changing the s from lowercase to uppercase. When I did this and ran my project, I no longer even get to my first page. I just get the 404 error as it's trying to look for my index.jsp. Any ideas on why changing struts.xml to lowercase is causing more problems than it's fixing?
My struts.xml file is in WebContent/WEB-INF/classes. My index.jsp in under WebContent.

Here is my struts.xml code

<strtus>
    <constant name="struts.devMode" value="true" />
    <package name="default" extends="struts-default">
        <action name="MyAction"
            class="com.Foo.MyAction"
            method="execute">
            <result name="success">/showTable.jsp</result>
        </action>
    </package>
</strtus>

Your struts.xml file should be in src folder. So change the file location to ProjectName/src with the file name struts.xml not Struts.xml.

Thanks, Amit Kumar