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("Please enter a valid Email Address")
		   return false
		}
		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Please enter a valid Email Address")
		   return false
		}
		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Please enter a valid Email Address")
		    return false
		}
		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Please enter a valid Email Address")
		    return false
		 }
		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Please enter a valid Email Address")
		    return false
		 }
		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Please enter a valid Email Address")
		    return false
		 }		
		 if (str.indexOf(" ")!=-1){
		    alert("Please enter a valid Email Address")
		    return false
		 }
 		 return true					
	}

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

function validate_form(thisform)
{
with (thisform)
{
if (validate_required(email,"Email must be filled out!")==false)
  {email.focus();return false}
  
if (echeck(email.value)==false)
  {email.focus();return false}
  
if (validate_required(first_name,"Please enter your first name")==false)
  {first_name.focus();return false}
  
if (validate_required(surname,"Please enter your surname")==false)
  {surname.focus();return false}
  
if (validate_required(company,"Please enter your company name")==false)
  {company.focus();return false}
  
if (validate_required(postcode,"Please enter your postcode")==false)
  {postcode.focus();return false}
  
if (validate_required(scientists,"Please enter the number of scientists on your site")==false)
  {scientists.focus();return false}
  
if (validate_required(password,"password must be filled out!")==false)
  {password.focus();return false}   
  
}
}