function checkSubmit(pType) {
			if(pType == 1) {
				// login
				if((document.forms['frmMain'].txtLogin.value.length < 1) || (document.forms['frmMain'].txtPassword.value.length < 1)){
					alert('Please enter your login details before clicking ok.');
					document.forms['frmMain'].txtLogin.focus();
					return;
				}
				else {
					document.forms['frmMain'].action = "after_login.asp"
					document.forms['frmMain'].submit();
				}
			}
			else if(pType == 2) {
				// sc number
				if(document.forms['frmMain'].txtSCNumber.value.length < 1) {
					alert('Please enter the SC number you wish to track.');
					document.forms['frmMain'].txtSCNumber.focus();
					return;
				}
				else {
					// make sure we have a valid number
					if(IsNumeric(document.forms['frmMain'].txtSCNumber.value)) {
						document.forms['frmMain'].action = "sc_tracking_number.asp"
						document.forms['frmMain'].submit();
					}
					else {
						alert('Please enter the number part only of your tracking number and click ok.');
						document.forms['frmMain'].txtSCNumber.focus();
						return;
					}
				}
			}
			else if(pType == 3) {
				// sa number
				if(document.forms['frmMain'].txtSANumber.value.length < 1) {
					alert('Please enter the SA number you wish to track.');
					document.forms['frmMain'].txtSANumber.focus();
					return;
				}
				else {
					// make sure we have a valid number
					if(IsNumeric(document.forms['frmMain'].txtSANumber.value)) {
						document.forms['frmMain'].txtConsignmentType.value = "SA"
						document.forms['frmMain'].action = "sas_tracking_number.asp"
						document.forms['frmMain'].submit();
					}
					else {
						alert('Please enter the number part only of your tracking number and click ok.');
						document.forms['frmMain'].txtSANumber.focus();
						return;
					}
				}
			}
			else if(pType == 4) {
				// sc number
				if(document.forms['frmMain'].txtSSNumber.value.length < 1) {
					alert('Please enter the SS number you wish to track.');
					document.forms['frmMain'].txtSSNumber.focus();
					return;
				}
				else {
					// make sure we have a valid number
					if(IsNumeric(document.forms['frmMain'].txtSSNumber.value)) {
						document.forms['frmMain'].txtConsignmentType.value = "SS"
						document.forms['frmMain'].action = "sas_tracking_number.asp"
						document.forms['frmMain'].submit();
					}
					else {
						alert('Please enter the number part only of your tracking number and click ok.');
						document.forms['frmMain'].txtSSNumber.focus();
						return;
					}
				}
			}
		}
		
		function IsNumeric(sText)
		{
		   var ValidChars = "0123456789.";
		   var IsNumber=true;
		   var Char;

		 
		   for (i = 0; i < sText.length && IsNumber == true; i++) 
		      { 
		      Char = sText.charAt(i); 
		      if (ValidChars.indexOf(Char) == -1) 
		         {
		         IsNumber = false;
		         }
		      }
		   return IsNumber;
		   
		   }