dom - javascript getElementsByName error for innerHTML -

i use dom multiple class names , pass function(with_value) access individual elements. uncaught typeerror cannot read propperty 'innerhtml' of undefined. code is:

<script>     var token = 1;                  var x = document.getelementsbyname("commpare_name");                  var y = document.getelementsbyname("compare_image");       function add_compare(num)             {  num=0;                        var = x[num].innerhtml.touppercase();                         alert(a);                     document.getelementbyid('name1').innerhtml = a;                     document.getelementbyid('name1').title =                     document.getelementbyid('pics1').src = x[num].src;                     = document.getelementbyid('view-details0').action;               } </script>  <span id="compare_name" name="compare_name" >no1</span> <form id="view-details0"> <input type="button" value="add compare" onclick="add_compare(1)"> </form>   <span id="compare_name" name="compare_name" >no1</span> <form id="view-details0"> <input type="button" value="add compare" onclick="add_compare(2)"> </form>  

edit:

<a class="description" id="name1" href="" target="_blank" title="add compare" ><span>add compare</span></a> 

the innerhtml , thee href of needs change

you giving wrong name in script

commpare_name - > compare_name