Syntax: required,optional
// inline comment 
/* multiline comments */
Statements: statement; {statement;statement}
Variables: Place holders for values. 
var var1,var2,var3;   // declares var1, var2, and var3 as an untyped variable
    var1 = expression;   // assigns the value of an expression to var1
var str1 = new String(); //declares str1 as a string variable
    str1 = "abcdef"; // assigns str1 the value abcdef
    str1.big(); // returns <big>abcdef</big>
    str1.concat("xxx"); //returns abcdefxxx
    str1.charAt(1); // returns b
    str1.charCodeAt(1); // returns 98, ascii for b
    str1.fixed(); // returns <tt>abcdef</tt>
    str1.indexOf("cd",0); // returns 2, c is the 2nd character
    str1.indexOf("z",0); // returns -1
    str1.length; // returns 6
    str1.match("ab"); // returns 6
    str1.replace("cd","xx"); // returns abxxef
    str1.search("c") // returns 2
    str1.search(/[c-z]||[a-c]/); // returns 2. /[c-z]/ is called a RegExp
    str1.substr(2,2) // returns cd, substr(start,length)
    str1.substring(2,3); // returns cd, substring(start,end)
    str1.slice(2,3); // returns cd, substring(start,end)
    arr1=str1.split("c");// arr1[0] returns ab, arr1[1] returns def
    str1.toUpperCase() // returns ABCDEF
    str1=str1 + 'hello' // str1=abcdefhello
    str1+= 'hello' // str1 = abcdefhello
    str1+= "\n" // str1 = abcdef + carriage return
var arr1 = new Array(value1,value2,value3...);
    arr1[0]  =value // assigns a value to an arr1[0]
    arr1[1.2]=value // assigns a value to an arr2[1.2]
    arr1['x']=value //assigns a value to arr3['x']
    arr1.reverse()//reverses arr1
    arr1.sort()//sorts arr1
Expressions: (expression) Returns a value. It can be a condition, an expression or constant.
    nbr1=(nbr2 operator nbr3)... // operators are: *,/,+,-,%
    nbr1=(8*3) // nbr1 = 24
    nbr1=(8/3) // nbr1 = 2
    nbr1=(8%3) // nbr1 = 2 (the remainder of 8/3)
    nbr1=(8+3) // nbr1 = 11
    nbr1=(8-3) // nbr1 = 5
    nbr1++     // nbr1 = nbr1 + 1
    nbr1+= 2   // nbr1 = nbr1 + 2
Conditions: (condition) // returns true or false, false is equal to 0.
    condition is: (var1 test var2) // test is: ==,>=,<=,!=
    test1=(8==3)       // false, 8=3
    test1=(8>=3)       // false
    test1=(8<=3)       // true
    test1=(8!=3)       // true, ! means not
    test1=!(8==3)      // true, ! means not
    test1=(8<3)        // false
    test1=(8>3)        // true
    test1=(8=3)||(8=8) // true, || means OR
    test1=(8=3)&&(8=8) // false, && means AND
    ~  // um?l
    ?:  // inline condition for if true
var date = new Date() //mydate is number of milliseconds since 1/1/1970, 00:00:00, 
    date // returns a date string in the format "Thu, 11 Jan 1996 06:20:00 GMT". 
    date.getDay();     // returns 0 = Sunday, 6=Saturday
    date.getMonth()    // returns 0 = January
    date.getFullYear() // returns 1970 - 9999
    date.getDate()     // returns 1 = 1st, 31=31st
    date.getHours()    // returns 0 = 23
    date.getMinutes()  // returns 0-59
    date.getSeconds()  // returns 0-59
    date.setDate(date2) // sets date to the date2 Date object
    date.setFullYear('1999') // sets the year to 1999
    date.setMonth(0) // sets the month to January
    date.setHours(0) // sets the time to midnight
    date.setMinutes(0)
    date.setSeconds(0)
    date.setTime(0) // ?????
    date.toDateString()) // returns Fri May 6 2005
    date.toLocaleDateString() // returns the date in your system format;
    date.toString() // returns Fri May 6 01:00:00 PST 2005
var obj1 = new Object() // Creates a generic object 
    obj1.prop="hello" // Creates a property called prop for obj1 and sets it to hello

Statements
alert (value) // displays a popup with value and ok button
confirm (value) // displays a popup with value, and ok/cancel buttons. Returns true or false
for (var1=1;var1>=1;var=var+1) statement
   {
   break   // exits the loop.
   continue     // executes next loop
   }
for (property in object) statements // loops through object.* 
function functionname (parameter,parameter) statements
   {
   return expression
   }
if (condition) {statement} else {statement}
prompt (var1,var2) // displays a textbox showing var1, ok/cancel buttons. Returns the textbox value
setTimeout (functionname,value) // executes functionname after value. value=Seconds/1000.
while (condition) statements
with (object) property = value
   Property references without an object use the default object
   with (Math) {var xx=sin(angle); replaces var xx=Math.sin(angle);var x2=Math.cos(angle);

JavaScript Built-in Objects
Built//in objects can be accessed by both the client and server. 

Math Provides numerical constants and mathematical functions. 
Document // The text within the HTML's <BODY>>tag
document.write('text') // writes text to the current window
document.links('anchorName') // returns the href of <a href='www.yahoo.com' name='anchorName'>xxxx</a>
document.links('anchorID') // returns the href of <a href='www.yahoo.com' ID='anchorName'>xxxx</a>
form   // An object for gathering and echoing data, created by HTML <FORM> tags. 
window // is the Explorer's window
window.status = 'string'; // Sets the window status to 'string'
window.locaton = 'http://www.yahoo.com'; // Redirects the window to yahoo
window.print(); // prints the current window
window.blur();  // puts the current window behind the previous window
window.close(); //prompts to close the current window
window.defaultStatus = 'yes'; // sets the window default status
wdw=window.open (href,handle,features);
    features are:,dependent=yes,fullscreen=yes,resizable=yes,
    height=100px,width=100px,left=0px,top=0px,
    status=yes,scrollbar=yes,toolbar=yes
popup=window.open() // creates a popup explorer window
popup.document.write("hello") // streams text to the popup
popup.document.write(" there") // streams more text
popup.window.focus() // brings the popup to the top
popup.window.close() // closes the popup