function checkform(myform)
{	
	if (myform.name.value == "")
	{ 
		alert("Please enter your Name.");
		myform.name.focus();
		return false;
	} 
	else if (myform.phone.value == "")
	{ 
	  	 alert("Please provide your Phone No.");
		 myform.phone.focus();
		 return false;
	}
	else if (myform.mobile.value == "")
	{ 
	     alert("Please provide your Mobile No.");
		 myform.mobile.focus();
		 return false;
	}
	else if (myform.email.value == "")
	{ 
		alert("You must provide an Email Address.");
		myform.email.focus();
		return false;
	}
  	return checkEmail(myform.email.value);
}

function checkEmail(email)
{
	if(email.indexOf("/")>-1)
	{
		alert("Email address has invalid character: /");
  	    return false;
	}
	if(email.indexOf(":")>-1)
	{
		alert("Email address has invalid character: :");
  	    return false;
	}
	if(email.indexOf(",")>-1)
	{
		alert("Email address has invalid character: ,");
  	    return false;
	}
	if(email.indexOf(";")>-1)
	{
		alert("Email address has invalid character: ;");
  	    return false;
	}
	if(email.indexOf("@")<0)
	{
		alert("Email address is missing @");
  	    return false;
	}
	if(email.indexOf("\.")<0)
	{
		alert("Email address is missing .");
  	    return false;
	}
	return true;
}