How To Add a Javascript Welcome Popup Box to blogger

1.Log in to your dashboard--> layout- -> Edit HTML 

2.Scroll down to where you see  </head>  tag. 

3.Now copy below code and paste it right above </head>  tag.

<script> function MYALERT() { alert("WELLCOME MESSAGE"); } MYALERT() </script>

Note : Remember to replace WELLCOME MESSAGE  with your real wellcome message.

Look at the example below;

your wellcome message will look like this.

 

4.Now save your template and you are done.