function emailvalidation(entered, alertbox)
{
with (entered)
{
apos=value.indexOf("@"); 
dotpos=value.lastIndexOf(".");
lastpos=value.length-1;
if (apos<1 || dotpos-apos<2 || lastpos-dotpos>3 || lastpos-dotpos<2) 
{if (alertbox) {alert(alertbox);} return false;}
else {return true;}
}
}

function emptyvalidation(entered, alertbox)
{
with (entered)
{
if (value==null || value=="")
{if (alertbox!="") {alert(alertbox);} return false;}
else {return true;}
}
}

function digitvalidation(entered, min, max, alertbox, datatype)
{
with (entered)
{
checkvalue=parseFloat(value);
if (datatype)
{smalldatatype=datatype.toLowerCase();
if (smalldatatype.charAt(0)=="i") 
{checkvalue=parseInt(value); if (value.indexOf(".")!=-1) {checkvalue=checkvalue+1}};
}
if ((parseFloat(min)==min && value.length<min) || (parseFloat(max)==max && value.length>max) || value!=checkvalue)
{if (alertbox!="") {alert(alertbox);} return false;}
else {return true;}
}
}

function formvalidation(thisform)
{
with (thisform)
{
if (emptyvalidation(name,"Please enter your name and re-submit")==false) {name.focus(); return false;};
if (digitvalidation(phone,10,12,"Please enter a contact telephone number and re-submit","I")==false) {phone.focus(); return false;};
if (emailvalidation(email,"Please enter a valid email address and re-submit")==false) {email.focus(); return false;};
if (emptyvalidation(enquiries,"Please enter a message and re-submit")==false) {enquiries.focus(); return false;};
}
}