Simple php code to create captcha

 How to create captcha using php code

In this tutorial we provie simple php code to create captcha.

php Code :

<?php
$alphaL=range("a","z");
$alphaU=range("A","Z");

$numD=range(500,50);
$numA=range(1,50);

$color=array("red","blue","green","yellow","pink","black","gray");
$face=array("Blackadder ITC","Pristina","arial","Edwardian Script ITC","Forte");

$rColor=array_rand($color);
$rFace=array_rand($face);
$rAlphaL=array_rand($alphaL);
$rAlphaU=array_rand($alphaU);
$rNumA=array_rand($numA);
$rNumD=array_rand($numD);

$res=$alphaL[$rAlphaL].$numA[$rNumA].$alphaU[$rAlphaU].$numD[$rNumD];



?>
<font 
color="<?php echo $color[$rColor];?>" 
size="+3" 
face="<?php echo $face[$rFace];?>">
<?php
echo $res;
?>
</font>


<script>
function valid()
{
  var cap = "<?php echo $res;?>";
  if(document.f1.uic.value == "")
  {
  alert("enter captcha value");
  document.f1.uic.focus();
  return false;
  }
  
  else if(document.f1.uic.value != cap)
  {
  alert("enter captcha value is wrong");
  document.f1.uic.focus();
  return false;
  }
  
  else(document.f1.uic.value == cap)
  {
  alert("enter captcha value is correct");
  }
}
</script>

<form action="" method="post" name="f1" onsubmit="return valid()">
<input name="uic" type="text" />
<input name="go" type="submit" value="Go" />
</form>