function isEmailAddr(email)
{
  var result = false
  var theStr = new String(email)
  var index = theStr.indexOf("@");
  if (index > 0)
  {
    var pindex = theStr.indexOf(".",index);
  if ((pindex > index+1) && (theStr.length > pindex+1))
	result = true;
  }
  return result;
}

function contact_form() 
{  
if(document.getElementById('phone_chkbox').checked==false && document.getElementById('email_chkbox').checked==false)
	{
		alert("Check how you wish to get information")
		document.getElementById('phone_chkbox').focus();				
		return (false);
	}

 if(document.contactform.name.value=="")
  {
    alert("Please enter Name");
    document.contactform.name.focus();
    return (false);
  }
  
	  if(document.contactform.phone.value=="" && document.getElementById('phone_chkbox').checked==true)
	  {
		alert("Please enter Phone Number");
		document.contactform.phone.focus();
		return (false);
	  }     
	  if(isNaN(document.getElementById('phone').value) || document.getElementById('phone').value.indexOf('.') >=0 )
	  {
		alert("Phone No should be numeric")				
		document.getElementById('phone').focus();
		document.getElementById('phone').value="";
		return (false);			
	  }		  
		
  	if (document.getElementById('email_chkbox').checked==true)
  	{
    	if (document.contactform.email.value == "")
		  {
			alert("Please enter your E-Mail");
			document.contactform.email.focus();
			return (false);
		  }		
		  		
		if (!isEmailAddr(document.contactform.email.value))
		{
			alert("Please enter a valid email address in the form: yourname@yourdomain.com");
			document.contactform.email.focus();
			return (false);
		}
  	}

 	if(document.getElementById('phone_chkbox').checked==true && document.getElementById('email_chkbox').checked==true)
	{
		if(document.contactform.phone.value=="")
		  {
			alert("Please enter Phone Number");
			document.contactform.phone.focus();
			return (false);
		  }  	 
	   if(isNaN(document.getElementById('phone').value) || document.getElementById('phone').value.indexOf('.') >=0 )
		{
			alert("Phone No should be numeric")				
			document.getElementById('phone').focus();
			document.getElementById('phone').value="";
			return (false);			
		}		
	
		if (document.contactform.email.value == "")
		  {
			alert("Please enter your E-Mail");
			document.contactform.email.focus();
			return (false);
		  }
		  		
		if (!isEmailAddr(document.contactform.email.value))
		{
			alert("Please enter a valid email address in the form: yourname@yourdomain.com");
			document.contactform.email.focus();
			return (false);
		}
	}

  if (document.contactform.query.value=="")
  {
    alert("Please enter your query");
    document.contactform.query.focus();
    return (false);
  }    
 	return true;     
}