$('.image', tb).click(function(){ 
var p='smile.gif';
formatText(iframe, 'InsertImage', p);
return false; });

 function formatText(iframe, command, option) {
        iframe.contentWindow.focus();
        try{
            iframe.contentWindow.document.execCommand(command, false, option);
        }catch(e){console.log(e)}
        iframe.contentWindow.focus();
    }