Error 500--Internal Server Error

java.lang.NumberFormatException: null
	at java.lang.Integer.parseInt(Integer.java:417)
	at java.lang.Integer.parseInt(Integer.java:499)
	at com.tobbnet.uye.action.UyeEditAction.execute(UyeEditAction.java:65)
	at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
	at com.tobbnet.base.CustomRequestProcessor.processActionPerform(CustomRequestProcessor.java:48)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
	at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
	at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
	at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
	at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:301)
	at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:184)
	at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3732)
	at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3696)
	at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
	at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
	at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2273)
	at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
	at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1490)
	at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)
	at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)