just do this , you need to remove char other than “numeric” and “.” form your string will do work for you
yourString = yourString.replace ( /[^\d.]/g, '' );
your final code will be
str1 = "test123.00".replace ( /[^\d.]/g, '' );
str2 = "yes50.00".replace ( /[^\d.]/g, '' );
total = parseInt(str1, 10) + parseInt(str2, 10);
alert(total);