Cannot run program “p4”: CreateProcess error=2, The system cannot find the file specified

I'm developing automate deployment script for Coldfusion project.

Tool: cruisecontrol.net, ant script
Source control: perforce

Executing the following ant script from cruisecontrol.net i'm getting this error:
"Cannot run program "p4": CreateProcess error=2, The system cannot find the file specified"

But its working fine from command line:

ant -f deployment.xml

deployment.xml file content:

<!-- Get Latest revision from perforce -->
<echo message="Perforce code base Get Latest revision Started"/>
<p4sync port="${p4.server}"
client="${p4.workspace}"
globalopts="${p4.password}"
user="${p4.username}"
view="${p4.branch}"/>
<echo message="Perforce code base Get Latest revision completed"/>

ccnet.config:

<project name="TestMGDeployment">
   <triggers>
      <intervalTrigger seconds="300" />
   </triggers>
   <tasks>
      <exec executable="C:\Apache\apache-ant-1.8.1\bin\ant.bat">
         <baseDirectory>C:\cruisecontrol\Projects</baseDirectory>
         <buildArgs>-f deployment.xml</buildArgs>
      </exec>
   </tasks>
</project>

Thanks,
Nagarajan