JS operation cookies write and read instance code

var c_name="value"; // Variable name
if ( > 0) {
c_start = (c_name + "=")
if (c_start != -1) {
c_start = c_start + c_name.length + 1
c_end = (";", c_start)
if (c_end == -1) c_end =
// ((c_start,c_end)+"<br>");
var sss= unescape((c_start, c_end)) // Get out the value
alert(sss)
}
}