function compare_fields(field1,field2) 
{
	var email1 = field1.value;
	var email2 = field2.value;
	if(email1 == email2) 
	{ 
		return true; 
	}
	alert("Both email fields must be identical.");
	
	return false;
}

function validate_required(field,alerttxt)
{
	with (field)
	{
		if (value==null||value=="")
  		{
  			alert(alerttxt);
  			return false
  		}

		else
		{
			return true
		}
	}
}
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)
	{
	   alert("Email address is in an incorrect format.")
	   return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
	{
	   alert("Email address is in an incorrect format.")
	   return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr)
	{
		alert("Email address is in an incorrect format.")
		return false
	}

	 if (str.indexOf(at,(lat+1))!=-1)
	 {
		alert("Email address is in an incorrect format.")
		return false
	 }

	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
	 {
		alert("Email address is in an incorrect format.")
		return false
	 }

	 if (str.indexOf(dot,(lat+2))==-1)
	 {
		alert("Email address is in an incorrect format.")
		return false
	 }
		
	 if (str.indexOf(" ")!=-1)
	 {
		alert("Email address is in an incorrect format.")
		return false
	 }
 		return true					
}

function validate_form(thisform)
{
	with (thisform)
	{
		if (validate_required(txt_first_name,"Please, write your first name.")==false)
  		{
  			txt_first_name.focus();
  			return false
  		}
		else
		if (validate_required(txt_last_name,"Please, write your last name.")==false)
  		{
  			txt_last_name.focus();
  			return false
  		}
		else
		if (validate_required(txt_email,"Please, write your email address.")==false)
  		{
  			txt_email.focus();
  			return false
  		}
		else
		if (echeck(txt_email.value)==false)
		{
			txt_email.value=""
			txt_email.focus()
			return false
	    }
		else
		if (validate_required(txt_email2,"Please, confirm your email address.")==false)
  		{
  			txt_email2.focus();
  			return false
  		}
		else
		if (echeck(txt_email2.value)==false)
		{
			txt_email2.value=""
			txt_email2.focus()
			return false
	    }
		else
		if (validate_required(txt_code,"Please, write your employer code.")==false)
  		{
  			txt_code.focus();
  			return false
  		}
		else
		if (validate_required(txt_company_name,"Please, write your company name.")==false)
  		{
  			txt_company_name.focus();
  			return false
  		}
		else
		if (compare_fields(txt_email,txt_email2)==false)
  		{
  			txt_email.value = "";
			txt_email2.value = "";
			txt_email.focus();
  			return false
  		}
	}
}