How to set and read value from SC web.config file

Question

I'd like to set a value into the sharePoint web config. I build a http module and I Need to read a value from the config file. I registered the module into the config file here:

 </security>
<validation validateIntegratedModeConfiguration="false" />
<modules runAllManagedModulesForAllRequests="true">
  <remove name="AnonymousIdentification" />
  <remove name="FileAuthorization" />
  <remove name="Profile" />
  <remove name="WebDAVModule" />
  <remove name="Session" />
  <add name="SPRequestModule" preCondition="integratedMode"  type="Microsoft.SharePoint.ApplicationRuntime.SPRequestModule, Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
  <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
  <add name="SharePoint14Module" preCondition="integratedMode" />
  <add name="LoadMaster" type="LoadMaster"/>
</modules>

Answer 1

read - use ConfigurationManager write - use SPWebConfigModification