title: Devextreme multiple form submitted
body: <p>I am using Devextreme forms with angular 2.
  I have two separate forms, but when i call submit button of first form or second form, both forms get validated. why?</p>
  
  <p><a href="https://i.stack.imgur.com/1orrY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1orrY.png" alt="enter image description here"></a></p>
  
  <p>Here is two different forms in html,</p>
  
  <pre><code>  &lt;form action="your-action" (submit)="onFormSubmit($event)"&gt;
          &lt;diav class="dx-fieldset"&gt;
              &lt;div class="dx-fieldset-header"&gt;Credentials&lt;/div&gt;
              &lt;div class="dx-field"&gt;
                  &lt;div class="dx-field-label"&gt;Login&lt;/div&gt;
                  &lt;div class="dx-field-value"&gt;
                      &lt;dx-text-box&gt; 
                          &lt;dx-validator&gt;
                              &lt;dxi-validation-rule type="required" message="Login is required"&gt;&lt;/dxi-validation-rule&gt;
                          &lt;/dx-validator&gt;
                      &lt;/dx-text-box&gt;
                  &lt;/div&gt;
              &lt;/div&gt;    
                    &lt;/div&gt;       
          &lt;dx-validation-summary id="summary"&gt;&lt;/dx-validation-summary&gt;        
          &lt;dx-button 
              id="button"
              text="Register"
              type="success"  
              [useSubmitBehavior]="true"&gt;
          &lt;/dx-button&gt;
      &lt;/form&gt;       
      &lt;form action="your-action" (submit)="onFormSubmit1($event)"&gt;
          &lt;div class="dx-fieldset"&gt;
              &lt;div class="dx-fieldset-header"&gt;Credentials&lt;/div&gt;
              &lt;div class="dx-field"&gt;
                  &lt;div class="dx-field-label"&gt;Login&lt;/div&gt;
                  &lt;div class="dx-field-value"&gt;
                      &lt;dx-text-box&gt; 
                          &lt;dx-validator&gt;
                              &lt;dxi-validation-rule type="required" message="Login is required"&gt;&lt;/dxi-validation-rule&gt;
                          &lt;/dx-validator&gt;
                      &lt;/dx-text-box&gt;
                  &lt;/div&gt;
              &lt;/div&gt;        
                    &lt;/div&gt; 
                &lt;dx-validation-summary id="summary"&gt;&lt;/dx-validation-summary&gt;
                  &lt;dx-button 
              id="button"
              text="Register"
              type="success"  
              [useSubmitBehavior]="true"&gt;
          &lt;/dx-button&gt;
      &lt;/form&gt;
  </code></pre>