Added submit button calls the earlier button's function itself - ruby-on-rails-3

Question

I'm working on Rails 3 app. Here a view displays all the excel files uploaded by user. A button to execute all the checkbox selected files was already present with delete for each file separately. Now I'm supposed to add a 'delete' button to delete the selected files. I've added the button n modified the function called by this form jus to display "in execute" and "in delete" for now to check if the second 'delete' button is functioanal. But every time delete is clicked it prints "in execute" only in cmd. I guess the AJAX related code written in the view 'list' is the problem.
Pls help!! Tell me why is it going to execute always?
The related code is here:
PS: I hav used if params[:commit]="Delete" & if params[:delete_button] also in controller.rb to but didnt help
list.html.erb (the view that displays all files)
<% if #files.length > 0 %>
<h2 id='comments'>Uploaded Excel Files are as listed below for Edit/Delete/Execution</h2>
<div id='checkone' class='hide'>Please check atleast one excel file to execute</div>
<% ajax_str = "new Ajax.Request('/account/execute_testcases', {asynchronous:true, evalScripts:true, onComplete:function(request){adjust_sidebar();Element.show('msg');Element.hide('waitid');Element.hide('disableexecuteid');Element.show('executeid');}, onLoading:function(request){Element.show('waitid');Element.hide('msg');Element.hide('executeid');Element.show('disableexecuteid');}, parameters:Form.serialize(this)}); return false;".html_safe %>
<%= form_for 'file_names', :url => {:controller => 'account', :action => 'execute_testcases'}, :remote => true, :html => {:name => 'frmExecute', :onsubmit => ajax_str }, :id =>'execute_tc' do |f| %>
<table>
<% if #file_count > 1 && #error_in_all_files == false %>
<tr>
<td>
<input type='checkbox' name='chkAll' onclick='checkAll();'>
<span class='text'>Check All/Decheck All</span>
</td>
</tr>
<% end %>
</table>
<table class='upload'>
<% for a in #files %>
<tr>
<td>
<% file_id = a.id.to_i %>
<% if(#excel_errors[file_id].nil? || #excel_errors[file_id].empty?) && a.file_type.to_i != 1 %>
<input type='checkbox' name = "excelfile[]" value="<%= a.excel_filename %>,<%= a.excel_filename_with_timestamp %>">
<% else %>
<input type='checkbox' name = "excelfile[]" value="<%= a.excel_filename %>,<%= a.excel_filename_with_timestamp %>" disabled=true>
<% end %>
<a href="open_excel_file/<%= a.id %>" title='Click to open' class='nodecoration'><%= a.excel_filename %></a>
</td>
<td>
<%= link_to(image_tag("/images/b_edit.png", :border => 0, :title => 'Edit'), :action => 'upload_file', :file_id => a.id) %>
</td>
<td>
<img src='/images/b_drop.png' border=0 title='Delete' onclick="return confirm('This will delete the related reports too. Are you sure to delete?');">
</td>
<td>
<%
if !#excel_errors[file_id].nil? && !#excel_errors[file_id].empty?
#joined_excel_errors = #excel_errors[file_id].join(', ')
%>
Error
<% end %>
</td>
</tr>
<tr id="excel_error_<%=file_id %>" style='display:none;'>
<td colspan=4>
<% if !#excel_errors[file_id].nil? && !#excel_errors[file_id].empty? %>
<div class="padder">
<% for error_value in #excel_errors[file_id] %>
<font color='maroon'><%= error_value %></font><br>
<% end %>
</div>
<% end %>
</td>
</tr>
<% end %>
<tr><td> </td></tr>
<tr>
<td>
<% if #error_in_all_files == false %>
<span class='executebutton' id='executeid'>
<%= f.submit "Execute", name: 'execute_button', :onclick =>"return checkSelected();" %>
</span>
<span class='deletebutton' id='deleteid'>
<%= f.submit "Delete", name: 'delete_button', :onclick =>"return checkSelected();" %>
</span>
<% end %>
<span id='disableexecuteid' class='executebutton' style='display:none;'>
<input type='submit' value="Execute" disabled="disabled">
</span>
<span id='waitid' style="display:none;" class='text'>
<br>Executing Test Cases...Please wait...<%= image_tag("/images/wait26trans.gif", :border => 0) %>
</span>
<span id='msg' style="display:none;" class='text'>
<br><br> Click here to <%= link_to 'View Test Results', {:controller => 'account', :action => 'recent_test_results'}, :class => 'brownlink' %>
</span>
</td>
</tr>
</table>
<span id='subject_list'>
</span>
<% end %>
<% else %>
No test case sheets found!
<br><br>
<%= link_to '>> Upload File', {:controller => 'account', :action => 'upload_file'}, :class => 'brownlink' %>
<% end %>
<% for i in 1..10 %>
<div> </div>
<% end %>
controller.rb
def execute_testcases
if !params[:execute_button].nil?
puts "in execute"
# file_names = []
# originalfile_filewithtime = []
# original_file_map = {}
# originalfile_filewithtime = params[:excelfile]
......
# SOME CODE HERE
......
# render :update do |page|
# page.replace_html :subject_list, :partial => 'show_output', :locals => {:new_file_map => #new_file_map}
# page.visual_effect :highlight, 'subject_list', :duration => 2
# flash[:display]=#execmsg
#end
# puts #execmsg
elsif !params[:delete_button].nil?
puts "in delete"
end
end

Answer 1

I realised it had to do something with the Form.serialize(this) of AJAX which serialises everything. ie It calls the function of first button in the view irrespective of no of submit buttons present