function objetoAjax(){
			var xmlhttp=false;
			try {
				xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
			} catch (e) {
				try {
					xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
				} catch (E) {
					xmlhttp = false;
				}
			}
			if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
				xmlhttp = new XMLHttpRequest();
			}
			return xmlhttp;
		}

	function resultadosBuscador(){
		
			if(	document.frm_busqueda.pais.value == 0 &&
			   	document.frm_busqueda.area.value == 0 &&
				document.frm_busqueda.institucion.value == 0 &&
				document.frm_busqueda.idioma.value == 0 ){
				
					alert("Seleccione alguna opcion de busqueda.");
					return false;
					
				}else{							

					document.frm_busqueda.submit();		
					
				}
                        
		
		}
		
	function cambiaInstitucion(area){

			divContainer1 = document.getElementById('buscador_combo_institucion');
			ajax=objetoAjax();
			ajax.open( "POST" , "includes/buscador.php" , true );
			ajax.onreadystatechange=function() {
					if (ajax.readyState==1) {
								divContainer1.innerHTML = '<span class="texto_sol">Espere ...</span>'
						}
					if (ajax.readyState==4) {
								divContainer1.innerHTML = ajax.responseText
						}
			}
			ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
			ajax.send("area_busqueda="+area)
		}

	function cambiaArea(institucion){
			divContainer2 = document.getElementById('buscador_combo_area');
			ajax=objetoAjax();
			ajax.open( "POST" , "includes/buscador.php" , true );
			ajax.onreadystatechange=function() {               			
					if (ajax.readyState==1) {
								divContainer2.innerHTML = '<span class="texto_sol">Espere ...</span>'
						}
					if (ajax.readyState==4) {
								divContainer2.innerHTML = ajax.responseText
						}
			}
			ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
			ajax.send("uni_busqueda="+institucion)
		}
		
	function cambiaPais(institucion){			
			divContainer2 = document.getElementById('buscador_combo_pais');
			ajax=objetoAjax();
			ajax.open( "POST" , "includes/buscador.php" , true );
			ajax.onreadystatechange=function() {               			
					if (ajax.readyState==1) {
								divContainer2.innerHTML = '<span class="texto_sol">Espere ...</span>'
						}
					if (ajax.readyState==4) {
								divContainer2.innerHTML = ajax.responseText
						}
			}
			ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
			ajax.send("institucion_busqueda="+institucion)
	}	
	
	function cambiaIdiomas(pais){	
			institucion = document.getElementById('institucion').value;
			divContainer2 = document.getElementById('buscador_combo_idioma');
			ajax=objetoAjax();
			ajax.open( "POST" , "includes/buscador.php" , true );
			ajax.onreadystatechange=function() {               			
					if (ajax.readyState==1) {
								divContainer2.innerHTML = '<span class="texto_sol">Espere ...</span>'
						}
					if (ajax.readyState==4) {
								divContainer2.innerHTML = ajax.responseText
						}
			}
			ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
			ajax.send("pais_busqueda="+pais+"&uni="+institucion)
	}