How do I disable/enable a form element?

enable or disable a form element using the .prop() method:
// Disable #div1



$( "#div1" ).prop( "disabled", true );



 



// Enable #div1



$( "#div").prop( "disabled", false );

How to Change colour on mouseover.

Hello.
The code to change colour (textbox,button,cell,tr etc). You can make a class in HTML design form and then call that function on code file.
Step 1:-
First of all make a css class as shown below:

<style type="text/css">

.normalRow
{
background-color:Red;
cursor:pointer;

.highlightRow
{
background-color:white;
cursor:pointer;
}
</style>

Step 2:-

Now call this css in code file like (this is for table row TR):

 tr1.Attributes.Add("onmouseover", "this.className=('highlightRow');");
 tr1.Attributes.Add("onmouseout", "this.className=('normalRow');");

Write a 'C' program to animate a circle?

The program in ‘C’ Programming language to draw a circle on the screen and animate it is as follows:

#include <stdio.h>

#include <conio.h>

#include <graphics.h>

#include <dos.h>

#define RADIUS 50

#define DELAY 20

void main()

{

            int x=0, y=0, gdriver=DETECT, gmode=4;

            clrscr();

            initgraph(&gdriver, &gmode, "C:\\TC\\BGI");

            while(!kbhit())

            {

                        for(x=0, y=0; x<getmaxy() && !kbhit();)

                        {

                                    circle(x++, y++, RADIUS);

                                    delay(DELAY);

                                    cleardevice();

                        }

                        cleardevice();

            }

            getch();

            closegraph();

}