In SharePoint 2010 how to hide columns in NewForm.aspx / EditForm.aspx / DispForm.aspx

Hide SharePoint Columns in New / Edit / View Form
Open the SharePoint Designer 2010, Go to the Corresponding List/ Library. 
Open the New/Edit / View Item Aspx Page in Edit In Advance Mode add the Following script 


<asp:Content ContentPlaceHolderId="PlaceHolderAdditionalPageHead" runat="server">

Now copy & paste this JavaScript code after above mentioned tag :

<script language="javascript" type="text/javascript">
_spBodyOnLoadFunctionNames.push("hideFields");
function findacontrol(FieldName) {
   var arr = document.getElementsByTagName("!");
   // get all comments
   for (var i=0;i < arr.length; i++ )
   {
      // now match the field name
      if (arr[i].innerHTML.indexOf(FieldName) > 0)
      {         return arr[i];      }
   }
}

function hideFields() {
   var control = findacontrol("Title");
   control.parentNode.parentNode.style.display="none";
   control = findacontrol("Leave Type");
   control.parentNode.parentNode.style.display="none";
   control = findacontrol("Manager Name");
   control.parentNode.parentNode.style.display="none";
}
</script>