Made enum value optional if the parameter is not required

build/index.html

@@ -120,8 +120,11 @@
       <td class='code'>${name}</td>
       <td>
         <select name='${name}'>
+          {{if required == false }}
+          <option selected='selected' value=''></option>
+          {{/if}}
           {{each allowableValues}}
-          {{if $value == defaultValue }}
+          {{if $value == defaultValue && required == true}}
           <option selected='selected' value='${$value}'>${$value}</option>
           {{else}}
           <option value='${$value}'>${$value}</option>

source/index.html.haml

@@ -77,8 +77,11 @@
     %td.code ${name}
     %td
       %select{:name => "${name}"}
+        {{if required == false }}
+        %option{:value => "", :selected => 'selected'}
+        {{/if}}
         {{each allowableValues}}
-        {{if $value == defaultValue }}
+        {{if $value == defaultValue && required == true }}
         %option{:value => "${$value}", :selected => 'selected'} ${$value}
         {{else}} 
         %option{:value => "${$value}"} ${$value}