Problema com tela modal do Bootstrap

<?= anchor("CadastroCliente/alterar/{$cliente['id']}","Alterar",array('data-toggle'=>"modal", 'data-target'=>"#AltCli"))?>

<!-- modal Alteração -->
<div class="modal" id="AltCli" tabindex="1" role="dialog" aria-labelledby="largeModal" aria-hidden="true">
  <div class="modal-dialog modal-lg">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="xmodal" aria-hidden="true">×</button>
        <h4 class="modal-title" id="myModalLabel">Alterar Cliente</h4>
      </div>
      <div class="modal-body">
        <?php 
        	echo form_open("CadastroCliente/alterar");
        	
        	echo form_label("Login","Login");
        	echo form_input(array(
				"id"        => "login",
				"name"      => "loginalt",
				"class"     => "form-control",
				"type"      => "text",
				"maxlength" => "60",
				"value" => set_value("login","")
			));
			echo form_error("login");
        
			echo form_label("email", "email");
			echo form_input(array(
				"id"		=> "email",
				"name"		=> "emailalt",
				"class"		=> "form-control",
				"type"		=> "email",
				"maxlength" => "60",
				"value" => set_value("email","")
			));
			echo form_error("email");
			
			echo form_label("Senha", "senha");
			echo form_input(array(
				"id"		=> "senha",
				"name"		=> "senhaalt",
				"class"		=> "form-control",
				"type"		=> "password",
				"maxlength" => "255",
				"value" => set_value("senha","")
			));
			echo form_error("senha");
			
			echo form_hidden("ucli", "1");
			echo '<hr>';
			echo form_label("Nome da Empresa","nome");
			echo form_input(array(
				"id"		=> "nome",
				"name"		=> "nomealt",
				"class"		=> "form-control",
				"type"		=> "text",
				"maxlength" => "255",
				"value" => set_value("nome","")
			));
			echo form_error("nome");
			
			echo form_label("Telefones","telefone");
			echo form_input(array(
				"id"		=> "telefone",
				"name"		=> "tel1alt",
				"class"		=> "form-control",
				"placeholder" => "Telefone 1",
				"type"		=> "phone",
				"maxlength" => "14"
			));
			echo form_input(array(
					"id"		=> "telefone",
					"name"		=> "tel2alt",
					"class"		=> "form-control",
					"placeholder" => "Telefone 2",
					"type"		=> "phone",
					"maxlength" => "14"
			));
			echo form_input(array(
					"id"		=> "telefone",
					"name"		=> "tel3alt",
					"class"		=> "form-control",
					"placeholder" => "Telefone 3",
					"type"		=> "phone",
					"maxlength" => "14"
			));
			
			echo '</div>';
			echo '<div class="col-md-12">';
			
			echo form_button(array(
				"class"   => "btn btn-large btn-primary",
				"content" => "Salvar Alterações",
				"type"    => "submit"
			));
			
			echo '</div>';
			
			echo form_close();
        
        
        ?>
      </div>
    </div>
  </div>
</div>