add: item.setAttribute('class', 'identity-popup-item'); item.setAttribute('accountname', accountName); 
context: function fillIdentityListPopup(popup){    var identities = GetIdentities();	    for (var i=0; i<identities.length; i++)    {		var identity = identities[i];		//dump(i + " = " + identity.identityName + "," +identity.key + "\n");        var item=document.createElement('menuitem');        item.setAttribute('value', identity.identityName);        item.setAttribute('id', identity.key);        popup.appendChild(item);    }}
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/09a2d7822fc61d1f652cdeede69a0301bcaec908/MsgComposeCommands.js/clean/mailnews/compose/resources/content/MsgComposeCommands.js