Magento – Fix Call to setTemplate() on a Non-Object in Home Page

My home.phtml file

echo $this->getLayout()->createBlock('banner/Monblock')
->setTemplate('banner/afficher.phtml')->toHtml();

my layout file.

<?xml version="1.0" ?>
<layout version="0.1.0">
  <test_adminhtml_index_index>
     <reference name="content">
             <block type="banner/Myblock"  name="afficher_monbloc"
                  template="banner/afficher.phtml"/>
                   <block type="banner/adminhtml_grid" name="banner" />
      </reference>

   </test_adminhtml_index_index>

   <reference name="content">
             <block type="banner/Monblock"  name="afficher_monbloc"
                  template="banner/afficher.phtml"/>
                   <block type="banner/adminhtml_grid" name="banner" />
      </reference>

       <default>
          <reference name="content">
          </reference>
      </default>
      <banner_index>
           <reference name="content">
               <block type="banner/Monblock"  name="afficher_monbloc"
                  template="banner/afficher.phtml"/>
                  <block type="test/test"  name="test"
                          template="test/tes2.phtml" />
           </reference>
      </banner_index>
</layout>

My block file

class Banner_Banner_Block_Monblock extends Mage_Core_Block_Template
{
     public function methodblock()
     {
         return 'informations about my block !!' ;
     }
}

config.xml

<?xml version="1.0"?>
  <config>
     <modules>
        <Banner_Banner>
          <version>1.0.0</version>
        </Banner_Banner>
     </modules>
     <frontend>
       <routers>
          <banner>
              <use>standard</use>
              <args>
                 <module>Banner_Banner</module>
                 <frontName>banner</frontName>
              </args>
           </banner>
       </routers>
       <layout>
            <updates>
                <Banner_Banner>
                    <file>Banner.xml</file>
                </Banner_Banner>
            </updates>
        </layout>   
    </frontend>
    <admin>
     <routers>
         <banner>
            <use>admin</use>
            <args>
               <module>Banner_Banner</module>
               <frontName>admintest</frontName>
            </args>
         </banner>
      </routers>
 </admin>
 <adminhtml>
   <layout>
      <updates>
          <banner>
              <file>banner.xml</file>
           </banner>
      </updates>
   </layout>
   <menu>
      <banner translate="title" module="adminhtml">
         <title>My Banner</title>
         <sort_order>100</sort_order>
         <children>
             <set_time>
                   <title>Add Banner</title>
                   <action>admintest/adminhtml_index</action>
              </set_time>
          </children>
       </banner>
    </menu>
</adminhtml>
     <global>
      <models>
<banner>
     <class>Banner_Banner_Model</class>
     <resourceModel>Banner_mysql4</resourceModel>
 </banner>
<banner_mysql4>
     <class>Banner_Banner_Model_Mysql4</class>
     <entities>
         <banner>
           <table>banner</table>
         </banner>
      </entities>
</banner_mysql4>
</models>
    <!-- allow the plugin to read and write -->
<resources>
        <!-- connection to write -->
        <test_write>
            <connection>
                <use>core_write</use>
            </connection>
        </test_write>
        <!-- connection to read -->
       <test_read>
          <connection>
             <use>core_read</use>
          </connection>
       </test_read>
</resources>
 <!-- -/- -->

            <blocks> 
              <Banner>

              <class>Banner_Banner_Block</class>
             </Banner>

            </blocks>

     </global> 
</config>