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+
+<h2>Some javascript functions...</h2>
+<p><font face="Arial" size="2">As all of us know javascript is the mostly used
+script language for web development. But we cann't say it is perfect one. Let
+see some functions that will help us to avoid some javascript
+problems....</font></p>
+<p><font face="Arial"><font size="2"><strong><font color=
+"#333399">typeof(a)</font></strong><br>
+　　　 Though the typeof operator can be used to find the type of objects, it has
+got some problems. so we can use the following global functions to wrap the
+typeof operator.</font></font></p>
+<p><font face="Arial"><font size="2"><font color=
+"#333399"><strong>isIEObject(a)</strong></font><br>
+Internet Explorer holds references to objects that are not actually javascript
+objects. So if we use the objects in javascript it will give error. But the
+typeof operator identifies them as javascript objects( problem!!!). Here we can
+use the isIEObject() function to identify those
+objects.</font></font><font face="Arial"><font size="2"><font color=
+"#FF6600">Script:</font></font></font><font face="Arial" color="#3333FF" size=
+"2">function isIEObject(a)<br>
+{<br>
+　 　return isObject(a) &amp;&amp; typeof a.constructor != 'function';<br>
+}</font></p>
+<p><br>
+<font face="Arial"><font size="2"><strong><font color=
+"#333399">isArray(a)</font></strong>This function returns true if a is an
+array, meaning that it was produced by the Array constructor or by the [ ]
+array literal notation.</font></font><font face="Arial" color="#FF6600" size=
+"2">Script:</font><font face="Arial"><font size="2"><font color=
+"#3333FF">function isArray(a)<br>
+{<br>
+　return isObject(a) &amp;&amp; a.constructor == Array;<br>
+}</font><br>
+<br>
+<strong><font color="#333399">isBoolean(a)</font></strong><br>
+This function returns true if a is one of the Boolean values, true or
+false.<br>
+<font color="#FF6600">Script:</font></font></font><font face="Arial" color=
+"#3333FF" size="2">function isBoolean(a)<br>
+{<br>
+　 　return typeof a == 'boolean';<br>
+}</font></p>
+<p><font face="Arial"><font size="2"><strong><font color=
+"#333366">isEmpty(a)</font></strong><br>
+This function returns true if a is an object or array or function containing no
+enumerable members.</font></font><font face="Arial"><font size="2"><font color=
+"#FF6633">Script:</font></font></font><font face="Arial" color="#3333FF" size=
+"2">function isEmpty(o)<br>
+{<br>
+　 　if (isObject(o))<br>
+　{<br>
+　　　 　 for (var i in o)<br>
+　 {<br>
+　　　　　 　　return false;<br>
+　　　 　 }<br>
+　 　}<br>
+　 　return true;<br>
+}</font></p>
+<p><br>
+<font face="Arial"><font size="2"><strong><font color=
+"#333399">isFunction(a)</font></strong><br>
+This function returns true if a is a function. Beware that some native
+functions in IE were made to look like objects instead of functions. This
+function does not detect that.Netscape is better behaved in this regard.<br>
+<font color="#FF6600">Script:</font></font></font><font face="Arial" color=
+"#3333FF" size="2">function isFunction(a)<br>
+{<br>
+　 　return typeof a == 'function';<br>
+}</font></p>
+<p><font face="Arial"><font size="2"><font color=
+"#333399"><strong>isNull(a)</strong></font><br>
+This function returns true if a is the null value.</font></font><font face=
+"Arial" color="#FF6600" size="2">Script:</font><font face="Arial" color=
+"#3333FF" size="2">function isNull(a)<br>
+{<br>
+　 　return typeof a == 'object' &amp;&amp; !a;<br>
+}</font></p>
+<p><font face="Arial"><font size="2"><font color="#3333CC"><strong><font color=
+"#333399">isNumber(a)</font></strong></font>This function returns true if a is
+a finite number. It returns false if a is NaN or Infinite. It also returns
+false if a is a string that could be converted to a number.<br>
+<font color="#FF6600">Script:</font></font></font><font face="Arial" color=
+"#3333FF" size="2">function isNumber(a)<br>
+{<br>
+　 　return typeof a == 'number' &amp;&amp; isFinite(a);<br>
+}</font></p>
+<p><font face="Arial"><font size="2"><strong><font color=
+"#333399">isObject(a)</font></strong><br>
+This function returns true if a is an object, array, or function. It returns
+false if a is a string, number, Boolean, null, or
+undefined.</font></font><font face="Arial" color="#FF6600" size=
+"2">Script:</font><font face="Arial" color="#3333FF" size="2">function
+isObject(a)<br>
+{<br>
+　　 return (typeof a == 'object' &amp;&amp; !!a) || isFunction(a);<br>
+}</font></p>
+<p><font face="Arial"><font size="2"><font color=
+"#333399"><strong>isString(a)</strong></font><br>
+This function returns true if a is a string.<br>
+<font color="#FF6600">Script:</font></font></font><font face="Arial" color=
+"#3333FF" size="2">function isString(a)<br>
+{<br>
+　　 return typeof a == 'string';<br>
+}</font></p>
+<p><font face="Arial"><font size="2"><strong><font color=
+"#333399">isUndefined(a)</font></strong>This function returns true if a is the
+undefined value. You can get the undefined value from an uninitialized variable
+or from an object's missing member.<br>
+<font color="#FF6633">Script:</font></font></font><font face=
+"Arial"><font size="2"><font color="#3333FF">function isUndefined(a)<br>
+{<br>
+　　 return typeof a == 'undefined';<br>
+}</font></font></font></p>