Primefaces avoid submitting multiple forms - jsf

Question

I am new to Primefaces and I am working on a requirement to open a dialog box when we click on the button.
I could able to open the dialog and submit the form. But here I am facing a new that form behind the modal dialog also get submitted when I am trying to submit the form in the modal. The form behind the modal is a pure html code and modal dialog form is written in primefaces.
Is there any chances to submit the form that is existing in the dialog and skip the form behind the dialog. Could anyone tell me the solution for this?
For clear understanding, I am submitting the code below
<form class="form-horizontal" action="${request.contextPath}/appLogin" role="form" method="POST" h:rendered="true">
<div class="form-group">
<div class="col-sm-12" align="center">
<font color="red"> <h:outputLabel
value="${SPRING_SECURITY_LAST_EXCEPTION.message}" />
</font>
</div>
</div>
<div class="form-group">
<div class="col-sm-12">
<label for="username">Username</label> <input type="text"
class="form-control" name="username" id="username"
placeholder="Enter your username" />
</div>
</div>
<div class="form-group">
<div class="col-sm-12">
<label for="pwd">Password</label> <input type="password"
class="form-control" name="password" id="password"
placeholder="Enter password" />
</div>
</div>
<div class="form-group">
<div class="col-sm-12">
<div class="row">
<div class="col-sm-6">
<input type="checkbox" name="remember" id="remember" />
<h:outputText value=" Remember Me" />
</div>
<div class="col-sm-6" align="right">
<p:commandLink value="Forgot Password?" id="loginforgotpasswordlink"
onclick="clearEmailForgotPasswordPopUp();" />
</div>
</div>
</div>
</div>
</form>
<p:dialog id="emailIdDialog" modal="true" widgetVar="emailIdDialog" width="400"
header="Email Id" appendTo="#(body)" resizable="false">
<ui:include src="/faces/validateEmailId.xhtml" />
</p:dialog>
<div class="form-group">
<p:outputLabel for="emailid1" value="Email" class="col-sm-3 control-label align-right" style="border: 0px solid green;padding-right: 0px;text-align: right;"></p:outputLabel>
<div class="col-sm-9" style="border: 0px solid red;padding-left:0px;">
<p:inputText type="text" id="emailid1"
name="emailid1" required="true" requiredMessage="Please enter an email address"
placeholder="Enter your email id" style="width:100%"/>
</div>
<p:spacer height="10px"></p:spacer>
<div class="text-right" style="padding-left: 0px;">
<p:commandButton value="Submit" update="messages,:emailIdValidation" style="float: right; margin-right: 15px;">
<f:actionListener binding="#{someClassBean.validateEmail()}" />
</p:commandButton>
</div>
</div>
</h:form>
When I am clicking the form submit button in modal dialog the other form also getting submitting.