Code:

<!-- Auto read more script Start -->
<script type='text/javascript'>
var thumbnail_mode = "yes"; //yes -with thumbnail, no -no thumbnail
summary_noimg = 430; //summary length when no image
summary_img = 340; //summary length when with image
img_thumb_height = 200;
img_thumb_width = 200;
</script>
<script type='text/javascript'>
//<![CDATA[
function removeHtmlTag(strx,chop){
	if(strx.indexOf("<")!=-1)
	{
		var s = strx.split("<");
		for(var i=0;i<s.length;i++){
			if(s[i].indexOf(">")!=-1){
				s[i] = s[i].substring(s[i].indexOf(">")+1,s[i].length);
			}
		}
		strx =  s.join("");
	}
	chop = (chop < strx.length-1) ? chop : strx.length-2;
	while(strx.charAt(chop-1)!=' ' && strx.indexOf(' ',chop)!=-1) chop++;
	strx = strx.substring(0,chop-1);
	return strx+'...';
}

function createSummaryAndThumb(pID){
	var div = document.getElementById(pID);
	var imgtag = "";
	var img = div.getElementsByTagName("img");
	var summ = summary_noimg;
        if(thumbnail_mode == "yes") {
	if(img.length>=1) {
		imgtag = '<span style="float:left; padding:0px 10px 5px 0px;"><img src="'+img[0].src+'" width="'+img_thumb_width+'px" height="'+img_thumb_height+'px"/></span>';
		summ = summary_img;
	}
	}
	var summary = imgtag + '<div>' + removeHtmlTag(div.innerHTML,summ) + '</div>';
	div.innerHTML = summary;
}
//]]>
</script>
<!-- Auto read more script End -->



5.  Now find this line <data:post.body/> and replace this line with the code.



<!-- Auto read more Start -->
<!-- http://www.BloggerSentral.com -->
<b:if cond='data:blog.pageType == &quot;item&quot;'>
<data:post.body/>
<b:else/>
<b:if cond='data:blog.pageType == &quot;static_page&quot;'>
<data:post.body/>
<b:else/>
<div expr:id='&quot;summary&quot; + data:post.id'><data:post.body/></div>
<script type='text/javascript'> createSummaryAndThumb(&quot;summary<data:post.id/>&quot;);
</script>
<a class='more' expr:href='data:post.url'>Read more ...</a>
</b:if>
</b:if>
<!-- Auto read more End -->