Prevent double form submission in QSO section

Introduces a submission state flag to prevent double submissions of the QSO form, disables the submit button during processing, and restores its state if the page visibility changes or fields are reset. Also adds handling to prevent Enter key from causing duplicate submissions.

assets/js/sections/qso.js

@@ -348,13 +348,54 @@ var favs={};
 	});
 
 	// Test Consistency value on submit form //
-	$("#qso_input").off('submit').on('submit', function(){
+	var isSubmitting = false;
+	$("#qso_input").off('submit').on('submit', function(e){
+		// Prevent double submission
+		if (isSubmitting) {
+			e.preventDefault();
+			return false;
+		}
+		
 		var _submit = true;
 		if ((typeof qso_manual !== "undefined")&&(qso_manual == "1")) {
 			if ($('#qso_input input[name="end_time"]').length == 1) { _submit = testTimeOffConsistency(); }
 		}
+		
+		if (_submit) {
+			// Mark as submitting and disable the submit button
+			isSubmitting = true;
+			var submitBtn = $(this).find('button[type="submit"]');
+			var originalText = submitBtn.data('original-text');
+			if (!originalText) {
+				// Store original text first time
+				originalText = submitBtn.html();
+				submitBtn.data('original-text', originalText);
+			}
+			submitBtn.prop('disabled', true);
+			submitBtn.html('<i class="fas fa-spinner fa-spin"></i> Saving...');
+		}
+		
 		return _submit;
 	})
+	
+	// Prevent Enter key from causing double submissions
+	$("#qso_input").on('keydown', function(e) {
+		if (e.key === 'Enter' && e.target.type !== 'textarea') {
+			if (isSubmitting) {
+				e.preventDefault();
+				return false;
+			}
+		}
+	});
+	
+	// Reset submission state when page becomes visible again (handles cases where submission gets stuck)
+	document.addEventListener('visibilitychange', function() {
+		if (!document.hidden && typeof isSubmitting !== 'undefined' && isSubmitting) {
+			setTimeout(function() {
+				resetSubmissionState();
+			}, 1000); // Wait 1 second before resetting to avoid interfering with legitimate submissions
+		}
+	});
 });
 
 var selected_sat;
@@ -477,8 +518,29 @@ function changebadge(entityname) {
 	}
 }
 
+/* Function: resetSubmissionState resets the form submission state */
+function resetSubmissionState() {
+	if (typeof isSubmitting !== 'undefined') {
+		isSubmitting = false;
+	}
+	var submitBtn = $('#qso_input button[type="submit"]');
+	if (submitBtn.length > 0) {
+		submitBtn.prop('disabled', false);
+		// Get the original text from the button or use a fallback
+		var originalText = submitBtn.data('original-text');
+		if (!originalText) {
+			// Store original text first time
+			originalText = submitBtn.html();
+			submitBtn.data('original-text', originalText);
+		}
+		submitBtn.html(originalText);
+	}
+}
+
 /* Function: reset_fields is used to reset the fields on the QSO page */
 function reset_fields() {
+	// Reset submission state
+	resetSubmissionState();
 
 	$('#locator_info').text("");
 	$('#country').val("");