[thelist] php equivavlent to javascript check

[Andrew]

Hi All where can I find a good resource to chech in PHP the same as this:

<script language="JavaScript">
<!--
function validate(frm){
					 
				     if(frm.BillTo_Name_First.value==""){
						 alert("You cannot leave First Name field empty");
						return false; 
					 }

					if(frm.email.value==""){
						 alert("You cannot leave Email field empty");
						 return false; 
					 }   
                   
					   txt=frm.email.value;

                         if (txt.indexOf("@")== -1){
                            alert("This email address seems wrong. Please"
                                  +" check the prefix and '@' sign.");
					      return false;
       
						}        
						return true;
	  }
</script>

Cheers
Andrew