function validate_form () {

if (document.Subscribe.email_from.value!="") 
{
if (document.Subscribe.email_from.value.indexOf("@")==-1 || document.Subscribe.email_from.value.indexOf(".")==-1 || document.Subscribe.email_from.value.indexOf(" ")!=-1 || document.Subscribe.email_from.value.length<6) 
{alert("Sorry, your e-mail address is not valid.\r\n");
document.Subscribe.email_from.focus();return false}
}
if(document.Subscribe.email_from.value.length <1)
{alert("You must enter a valid e-mail address.\r\n")
document.Subscribe.email_from.focus();return false}

if(document.Subscribe.Name.value.length <1)
{alert("You left the Name field blank")
document.Subscribe.Name.focus();return false}

if(document.Subscribe.Postcode.value.length <1)
{alert("You left the Postcode field blank")
document.Subscribe.Postcode.focus();return false}

if(document.Subscribe.Phone.value.length <3)
{alert("You must enter a complete main phone number.")
document.Subscribe.Phone.focus();return false}	

if(document.Subscribe.Referer.value.length <1)
{alert("You left the How Did You Find Us field blank")
document.Subscribe.Referer.focus();return false}

}