Cannot retrieve definition for form bean RegisterationForm on action /ShowWelcomePage

struts-config.xml is -

<global-forwards>
<forward name="welcome" path="/Welcome.jsp"/>
</global-forwards>

<action-mappings>
<action path="/ShowWelcomePage"
parameter="/Welcome.jsp"
type="org.apache.struts.actions.ForwardAction" />

<action path="/ShowWelcomePage"
type="Struts.pack.FormAction"
name="RegisterationForm"
scope="request"
validate="true"
input="/Welcome.jsp">
<forward name="success" path="/Success.jsp" />
</action>

</action-mappings>

AND Welcome.jsp is as follows -

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>

<html:html xhtml="true">
<body>
<div align="center">

<h2><bean:message key="prompt.formpage.title"/></h2>

<html:errors/>

<html:form action="/ShowWelcomePage" method="GET">

<bean:message key="prompt.customer.login_name"/>:
<html:text property="loginName" size="16" maxlength="16"/>

<bean:message key="prompt.customer.password"/>:
<html:password property="password" size="16" maxlength="16"/>

<bean:message key="prompt.customer.email"/>:
<html:password property="email" size="16" maxlength="16"/>

<html:submit property="step">
<bean:message key="button.save"/>
</html:submit>

<html:cancel property="step">
<bean:message key="button.cancel"/>
</html:cancel>

</div>
</html:form>
</body>
</html:html>

please solve the error - "Cannot retrieve definition for form bean RegisterationForm on action /ShowWelcomePage"