Someone

<form onsubmit="return false;">
<input type="hidden" id="input-15" onBlur="changeBack('input-15','text-15')" />

</form>

<span style="displ" id="text-15"  ondblclick="change('input-15','text-15');" style="width:100%;display:block;">Double Click Me</span>

<script type="text/javascript">
/*<![CDATA[*/

function change(input,text) {

var textNode = document.getElementById(text);
var textValue = textNode.firstChild.nodeValue;
var textboxNode = document.getElementById(input);


  textboxNode.setAttribute('value', textValue);
  textNode.style.display = 'none';
  textboxNode.setAttribute('type','text');
  textboxNode.focus();

}


function changeBack(input,text) {

var textNode = document.getElementById(text);
var textValue = textNode.firstChild.nodeValue;
var textboxNode = document.getElementById(input);


  textNode.firstChild.nodeValue = textboxNode.value;
  textNode.style.display = 'block';
  textboxNode.setAttribute('type', 'hidden');

}
/*]]>*/
</script>