// JavaScript Document

function remove_text()
{

	var c_postcode;
	c_postcode=document.getElementById("post_code");	
	
      c_string="SW20";
	c_string2=document.getElementById("post_code").value;

	if (c_string==c_string2)
	{ 
		c_postcode.style.color="black";
		c_postcode.value="";
	}
}

function set_text()
{
	
	var c_postcode;
	c_postcode=document.getElementById("post_code");	
	
	if (c_postcode.value=="")
	{
		c_postcode.style.color="grey";
		c_postcode.value="SW20";
	}
}



function echeck(str) 
{

        var at="@"
        var dot="."
        var lat=str.indexOf(at)
        var lstr=str.length
        var ldot=str.indexOf(dot)
        
  		if (str.indexOf(at)==-1)
  		{           
           return false
        }

        if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
  		{   
           return false
        }

        if (str.indexOf(at,(lat+1))!=-1)
        {
            return false
        }

        if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
        {   
            return false
        }

        if (str.indexOf(dot,(lat+2))==-1)
        {
            return false
        }
        
        if (str.indexOf(" ")!=-1)
  		{   
            return false
        }

          return true                    
 }
 
 function check_form()
{

  var v_success=true;
  var u_name;
  var u_email;
  
  try
  {
    u_name=document.getElementById("users_name").value;
    u_email=document.getElementById("users_email_addr").value;
  }
  catch(err)
  {
    u_name="not_found";
    u_email="not_found";
  }
  
  if(u_name=="")
  {
    alert("Please enter your name");
    v_success=false;
  }
  else if (u_email=="")
  {
    alert("Please enter your email address");
    v_success=false;
  }
  else if (echeck(u_email)==false)
  {
    alert("Please check your email address.");
    v_success=false;
  }
  else if(document.getElementById("ad-reply").value=="")
  {
    alert("Please enter your response to this advert.");
    v_success=false;
  }
  
  return v_success;
}

function go_back(a)
{
	history.back();
	return false;
}

function FormValid()
{
  var valid=true;
  
  if (document.getElementById("email").value=="")
  {
    alert("Please enter your email address.");
    valid=false;
  }

  else if (document.getElementById("password").value=="")
  {
    alert("Please enter your password.");
    valid=false;
  }
  
  return valid;
}