var errormsg;
var alphaChars="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ ";
var numChars="0123456789.";
function Trim(sString)
{
    return(sString.replace(/(^\s*)|(\s*$)/g, ""));
}
function chField(form, field, type, message)
{ 
  if(type == "mandatory")
  {     source=eval("document."+form+"."+field+".value");
     if ( Trim(source)=="" )
       { 
         errormsg+=message+'\n';
         return false;
       }
     else return true;      
  }
       
 if(type == "number")
  {   tmpsource=eval("document."+form+"."+field+".value");
       source=Trim(tmpsource); 
     if (source =="")
       {
	return true;
       } else {
	for( a3=0; a3 < source.length; a3++)
	{
		d3 = source.charAt(a3);
      		pos=numChars.indexOf(d3);
		if(pos == -1){
			errormsg+=message+'\n';
			return false;
		}
	}
     }
     return true;
  } 
  
  if(type=="null")
  {
       source=eval("document."+form+"."+field+".value");
     if (Trim(tmpsource) =="")
       { return true;
       }
     else {
	errormsg+=message+'\n';
     	return false;
     }
 }
 if(type=="select")
 {   	
   tmpSelected =  eval("document."+form+"."+field+".selectedIndex");
   if (tmpSelected != "-1" && tmpSelected != "0") {
     return true;
   }	 	
   errormsg+=message+'\n';
   return false;
 }
 if(type=="radio")
 {   	
   var tmplength = 0;
   var isChecked = false;
   tmplength = eval("document."+form+"."+field+".length");
   for (var i = 0; i < tmplength; i++) {     	
     isChecked = eval("document."+form+"."+field+"["+i+"]"+".checked");
     if (isChecked == true) {
	return true;
     }   
   }
   errormsg+=message+'\n';
   return false;
 }
 if(type=="checkbox")
{
   var tmplength = 0;
   var isChecked = false;
   tmplength = eval("document."+form+"."+field+".length");
	for (var i = 0; i < tmplength; i++)
	{
	     isChecked = eval("document."+form+"."+field+"["+i+"]"+".checked");
		     if (isChecked == true) {
			return true;
		     }   
	}
   errormsg+=message+'\n';
   return false;
}
}