function checkForm() {
  bIsValid = false;
  sError = "";
  
  //REGEX PATTERNS
  datePatt 		= new RegExp("^([1-9]|0[1-9]|[12][0-9]|3[01])[.\/]([1-9]|0[1-9]|1[012])[.\/](20[0-9][0-9])$");
  emailPatt		= new RegExp("^([a-zA-Z0-9_-]+\.?)+@([a-zA-Z0-9_-]+\.)+[a-zA-Z]{2,4}$"); 
  phonePatt 	= new RegExp("^([\+]?[ 0-9]+)$"); // Phone must not include non numeric characters
  agePatt		= new RegExp("^([1-9]{1,3})$"); //Age must be a reasonable number
  timePatt		= new RegExp("^([1-9]|0[0-9]|1[0-9]|2[0-3])[:.]([0-9]|0[0-9]|[1-5][0-9])$");
  
 
  //Date Validation
  if ((date = $('#txtDate').val()) == "")   
  	sError += "Please enter prefered date for your appointment\n"; 
  else if (!datePatt.test(date))  
  	sError = "Date format must be dd/mm/yyyy\n";
  else
  {
		var darr = date.split("/");  
		var du = new Date();
		du = du.setFullYear(darr[2], darr[1], darr[0]);
		var today = new Date();
		
		if(du < today)
			sError = "Please specify future date\n";
  }
	
  //Time Validation
  if ((time = $('#txtTime').val()) == "")   
  	sError += "Please enter prefered appointment time\n"; 
  else if (!timePatt.test(time)) 
  	sError = "Time format must be hh:mm \n";
	
  //Name Validation
  if ((name = $('#txtName').val()) == "") 
    sError += "Please enter your name \n";
	
  //Age Validation
  if ((age = $('#txtAge').val()) == "")   
  	sError += "Please enter your age\n"; 
  else if (!agePatt.test(age)) 
  	sError = "Age must be a reasonable number\n";
	
  //Gender Validation
  if ((gender = $('#selectGender').val()) == "")   
  	sError += "Please select your gender\n"; 
  
  //Address Validation
  /*if ((address = $('#txtAddress').val()) == "")   
  	sError += "Please enter your address\n";*/

  //Phone Validation     
  if ((phone = $('#txtPhone').val()) == "" ) 
  	 sError += "Please enter phone number\n"; 
  else if (!phonePatt.test(phone))    
   	 sError += "Phone must not include non numeric characters\n";

  //Email Validation     
  if ((email = $('#txtEmail').val()) != "" ) 
  {  
  	if (!emailPatt.test(email))    
   		sError += "Your E-Mail address is not correct\n";     
  }
 
  //Captcha Validation  
  if ($('#captcha_code').val() == "") 
    sError += "Please enter Antispam code.\n";             

  if (sError == "")  
    bIsValid = true;
  else
    alert(sError);
  
  return bIsValid;  

}