User753101303 posted
Hi,
The last '' is a single quote in your string and you need to add a 3rd one to really close the string. Anyway it is misplaced (should be before the > character):
SELECT '<a href=''http://localhost:1501/test.aspx?No='+CAST(@ENo AS varchar(10)) + '''>'
Edit: or it could be clearer to use double quotes ie :
SELECT '<a href="http://localhost:1501/test.aspx?No='+CAST(@ENo AS varchar(10)) + '">'