Helper in other helper

Hello everyone,

in my view, I wrap a form_for around a model:

<% form_for(:
) do |f| %>

Now I repeat the following very often why I would like to extract it
into a helper:

<%= f.text_field :field_1, :class=>"css_class"%>
<span class="css_class2">xxx</span>

Therefore, I packed it into a helper. Unfortunately, it does not get
interpreted as Code but html text:

def textfield_helper(input1, input2)
returnarray << f.text_field :#{input1}, :class=>\"css_class\"
returnarray << "<span class=\"css_class2\">"
returnarray << xxx
returnarray << "</span>"

Any ideas how to rephrase this: returnarray <<
f.text_field :#{input1}, :class=>\"css_class\" line?
Everything else seems to be ok!
Thank you very much in advance,