function submit_page_change() {

 var url = self.location.href;
 var search = window.location.search;
 var page = document.getElementById("pagedropdown").value;

 var curl =  url.replace(/\?.+/gi,"");
 var csearch =  search.replace(/(\&|\?)pageno\=.+/gi,"");

 if (csearch != '') { 
   var curi = curl + csearch + '&pageno=' + page;
 } else {
   var curi = curl + '?pageno=' + page;
 }

self.location = curi;
}

function search_ProdCode() {

 var queryform = document.getElementById("prodcode").value;
 var query = queryform.replace(/(^ +|^ )/gi,"");

 if (query == '') {
 alert("No query entered.")
 return
 }

 var curi = 'index.php' + '?search_code=' + query;

self.location = curi;
}

function search_ProdDesc() {

 var queryform = document.getElementById("proddesc").value;
 var query = queryform.replace(/(^ +|^ )/gi,"");

 if (query == '') {
 alert("No query entered.")
 return
 }

 var curi = 'index.php' + '?search_desc=' + query;

self.location = curi;
}