function entrarelem(a,b){if(a.value==b)a.value=""}function reemplazar(a,b,e){var c,d,f=0;d=a.length;newcadena="";for(c=0;c<d;c++)newcadena=a.charAt(c)==b?newcadena+e:newcadena+a.charAt(c),f++;return newcadena}function dejarelem(a,b){cadena=a.value;if(""==reemplazar(a.value," ",""))a.value=b};